diff --git a/.azure/pipelines/components-e2e-tests.yml b/.azure/pipelines/components-e2e-tests.yml
index 322649488141..ed817d303921 100644
--- a/.azure/pipelines/components-e2e-tests.yml
+++ b/.azure/pipelines/components-e2e-tests.yml
@@ -42,6 +42,7 @@ stages:
         cancelTimeoutInMinutes: 30
         buildArgs: -all -test /p:SkipHelixReadyTests=true /p:SkipIISNewHandlerTests=true /p:SkipIISTests=true
                    /p:SkipIISExpressTests=true /p:SkipIISNewShimTests=true /p:RunTemplateTests=false
+                   /p:RunQuarantinedTests=true
         beforeBuild:
         - powershell: "& ./src/Servers/IIS/tools/UpdateIISExpressCertificate.ps1; & ./src/Servers/IIS/tools/update_schema.ps1"
           displayName: Setup IISExpress test certificates and schema
diff --git a/src/Components/test/E2ETest/Infrastructure/WebDriverExtensions/WebDriverExtensions.cs b/src/Components/test/E2ETest/Infrastructure/WebDriverExtensions/WebDriverExtensions.cs
index 0d0067f6c1c2..969082ceb896 100644
--- a/src/Components/test/E2ETest/Infrastructure/WebDriverExtensions/WebDriverExtensions.cs
+++ b/src/Components/test/E2ETest/Infrastructure/WebDriverExtensions/WebDriverExtensions.cs
@@ -15,15 +15,6 @@ public static void Navigate(this IWebDriver browser, Uri baseUri, string relativ
         {
             var absoluteUrl = new Uri(baseUri, relativeUrl);
 
-            if (noReload)
-            {
-                var existingUrl = browser.Url;
-                if (string.Equals(existingUrl, absoluteUrl.AbsoluteUri, StringComparison.Ordinal))
-                {
-                    return;
-                }
-            }
-
             browser.Navigate().GoToUrl("about:blank");
             browser.Navigate().GoToUrl(absoluteUrl);
         }
diff --git a/src/Components/test/E2ETest/ServerExecutionTests/CircuitGracefulTerminationTests.cs b/src/Components/test/E2ETest/ServerExecutionTests/CircuitGracefulTerminationTests.cs
index 0665d6346d23..1b326af871ea 100644
--- a/src/Components/test/E2ETest/ServerExecutionTests/CircuitGracefulTerminationTests.cs
+++ b/src/Components/test/E2ETest/ServerExecutionTests/CircuitGracefulTerminationTests.cs
@@ -26,6 +26,8 @@ public CircuitGracefulTerminationTests(
             ITestOutputHelper output)
             : base(browserFixture, serverFixture, output)
         {
+            // The browser won't send the disconnection message if it's headless
+            browserFixture.EnsureNotHeadless = true;
         }
 
         public TaskCompletionSource<object> GracefulDisconnectCompletionSource { get; private set; }
@@ -65,7 +67,7 @@ public async Task ReloadingThePage_GracefullyDisconnects_TheCurrentCircuit()
             Assert.Contains((Extensions.Logging.LogLevel.Debug, "CircuitDisconnectedPermanently"), Messages);
         }
 
-        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/23015")]
+        [Fact]
         public async Task ClosingTheBrowserWindow_GracefullyDisconnects_TheCurrentCircuit()
         {
             // Arrange & Act
@@ -73,6 +75,7 @@ public async Task ClosingTheBrowserWindow_GracefullyDisconnects_TheCurrentCircui
             await Task.WhenAny(Task.Delay(10000), GracefulDisconnectCompletionSource.Task);
 
             // Assert
+            Assert.True(GracefulDisconnectCompletionSource.Task.IsCompletedSuccessfully);
             Assert.Contains((Extensions.Logging.LogLevel.Debug, "CircuitTerminatedGracefully"), Messages);
             Assert.Contains((Extensions.Logging.LogLevel.Debug, "CircuitDisconnectedPermanently"), Messages);
         }
diff --git a/src/Components/test/E2ETest/ServerExecutionTests/ComponentHubInvalidEventTest.cs b/src/Components/test/E2ETest/ServerExecutionTests/ComponentHubInvalidEventTest.cs
index 7c573a1362fc..3cc5c8a117d6 100644
--- a/src/Components/test/E2ETest/ServerExecutionTests/ComponentHubInvalidEventTest.cs
+++ b/src/Components/test/E2ETest/ServerExecutionTests/ComponentHubInvalidEventTest.cs
@@ -33,7 +33,7 @@ protected override async Task InitializeAsync()
             Assert.Equal(2, Batches.Count);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task DispatchingAnInvalidEventArgument_DoesNotProduceWarnings()
         {
             // Arrange
@@ -59,7 +59,7 @@ await Client.ExpectCircuitError(() => Client.HubConnection.SendAsync(
             Assert.Contains(Logs, l => (l.LogLevel, l.Exception?.Message) == (LogLevel.Debug, "There was an error parsing the event arguments. EventId: '3'."));
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task DispatchingAnInvalidEvent_DoesNotTriggerWarnings()
         {
             // Arrange
@@ -98,7 +98,7 @@ await Client.ExpectCircuitError(() => Client.HubConnection.SendAsync(
                 "There is no event handler associated with this event. EventId: '1990'. (Parameter 'eventHandlerId')"));
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task DispatchingAnInvalidRenderAcknowledgement_DoesNotTriggerWarnings()
         {
             // Arrange
diff --git a/src/Components/test/E2ETest/ServerExecutionTests/HeadModificationPrerenderingTest.cs b/src/Components/test/E2ETest/ServerExecutionTests/HeadModificationPrerenderingTest.cs
index 609a2b4c7902..ab29926a26f4 100644
--- a/src/Components/test/E2ETest/ServerExecutionTests/HeadModificationPrerenderingTest.cs
+++ b/src/Components/test/E2ETest/ServerExecutionTests/HeadModificationPrerenderingTest.cs
@@ -9,7 +9,7 @@
 using Xunit;
 using Xunit.Abstractions;
 
-namespace Microsoft.AspNetCore.Components.E2ETests.ServerExecutionTests
+namespace Microsoft.AspNetCore.Components.E2ETest.ServerExecutionTests
 {
     public class HeadModificationPrerenderingTest : ServerTestBase<BasicTestAppServerSiteFixture<DeferredComponentContentStartup>>
     {
diff --git a/src/Components/test/E2ETest/ServerExecutionTests/InteropReliabilityTests.cs b/src/Components/test/E2ETest/ServerExecutionTests/InteropReliabilityTests.cs
index 11f401c3444a..5b7c6bba95c6 100644
--- a/src/Components/test/E2ETest/ServerExecutionTests/InteropReliabilityTests.cs
+++ b/src/Components/test/E2ETest/ServerExecutionTests/InteropReliabilityTests.cs
@@ -36,7 +36,7 @@ protected override async Task InitializeAsync()
             Assert.Equal(2, Batches.Count);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task CannotInvokeNonJSInvokableMethods()
         {
             // Arrange
@@ -57,7 +57,7 @@ await Client.InvokeDotNetMethod(
             await ValidateClientKeepsWorking(Client, Batches);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task CannotInvokeNonExistingMethods()
         {
             // Arrange
@@ -78,7 +78,7 @@ await Client.InvokeDotNetMethod(
             await ValidateClientKeepsWorking(Client, Batches);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task CannotInvokeJSInvokableMethodsWithWrongNumberOfArguments()
         {
             // Arrange
@@ -99,7 +99,7 @@ await Client.InvokeDotNetMethod(
             await ValidateClientKeepsWorking(Client, Batches);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task CannotInvokeJSInvokableMethodsEmptyAssemblyName()
         {
             // Arrange
@@ -120,7 +120,7 @@ await Client.InvokeDotNetMethod(
             await ValidateClientKeepsWorking(Client, Batches);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task CannotInvokeJSInvokableMethodsEmptyMethodName()
         {
             // Arrange
@@ -142,7 +142,7 @@ await Client.InvokeDotNetMethod(
             await ValidateClientKeepsWorking(Client, Batches);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task CannotInvokeJSInvokableMethodsWithWrongReferenceId()
         {
             // Arrange
@@ -182,7 +182,7 @@ await Client.InvokeDotNetMethod(
             await ValidateClientKeepsWorking(Client, Batches);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task CannotInvokeJSInvokableMethodsWrongReferenceIdType()
         {
             // Arrange
@@ -213,7 +213,7 @@ await Client.InvokeDotNetMethod(
             await ValidateClientKeepsWorking(Client, Batches);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task ContinuesWorkingAfterInvalidAsyncReturnCallback()
         {
             // Arrange
@@ -242,7 +242,7 @@ await Client.HubConnection.InvokeAsync(
             await ValidateClientKeepsWorking(Client, Batches);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task JSInteropCompletionSuccess()
         {
             // Arrange
@@ -271,7 +271,7 @@ await Client.HubConnection.InvokeAsync(
             Assert.Equal(LogLevel.Debug, entry.LogLevel);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task JSInteropThrowsInUserCode()
         {
             // Arrange
@@ -304,7 +304,7 @@ await Client.HubConnection.InvokeAsync(
             await ValidateClientKeepsWorking(Client, Batches);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task MalformedJSInteropCallbackDisposesCircuit()
         {
             // Arrange
@@ -339,7 +339,7 @@ await Client.ExpectCircuitErrorAndDisconnect(async () =>
             });
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task CannotInvokeJSInvokableMethodsWithInvalidArgumentsPayload()
         {
             // Arrange
@@ -360,7 +360,7 @@ await Client.InvokeDotNetMethod(
             await ValidateClientKeepsWorking(Client, Batches);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task CannotInvokeJSInvokableMethodsWithMalformedArgumentPayload()
         {
             // Arrange
@@ -381,7 +381,7 @@ await Client.InvokeDotNetMethod(
             await ValidateClientKeepsWorking(Client, Batches);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task DispatchingEventsWithInvalidPayloadsShutsDownCircuitGracefully()
         {
             // Arrange
@@ -405,7 +405,7 @@ await Client.ExpectCircuitErrorAndDisconnect(async () =>
             });
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task DispatchingEventsWithInvalidEventDescriptor()
         {
             // Arrange
@@ -429,7 +429,7 @@ await Client.ExpectCircuitErrorAndDisconnect(async () =>
             });
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task DispatchingEventsWithInvalidEventArgs()
         {
             // Arrange
@@ -461,7 +461,7 @@ await Client.ExpectCircuitErrorAndDisconnect(async () =>
             });
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task DispatchingEventsWithInvalidEventHandlerId()
         {
             // Arrange
@@ -495,7 +495,7 @@ await Client.ExpectCircuitErrorAndDisconnect(async () =>
             });
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task EventHandlerThrowsSyncExceptionTerminatesTheCircuit()
         {
             // Arrange
diff --git a/src/Components/test/E2ETest/ServerExecutionTests/PrerenderingTest.cs b/src/Components/test/E2ETest/ServerExecutionTests/PrerenderingTest.cs
index f5961126c68d..36ca4f14f55b 100644
--- a/src/Components/test/E2ETest/ServerExecutionTests/PrerenderingTest.cs
+++ b/src/Components/test/E2ETest/ServerExecutionTests/PrerenderingTest.cs
@@ -135,7 +135,7 @@ public void CanAccessAuthenticationStateDuringStaticPrerendering(string initialU
             Browser.Equal($"Hello, {interactiveUsername ?? "anonymous"}!", () => Browser.Exists(By.TagName("h1")).Text);
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/35449")]
         public async Task NoHotReloadListenersAreOrdinarilyRegistered()
         {
             Navigate("/prerendered/prerendered-transition");
diff --git a/src/Components/test/E2ETest/ServerExecutionTests/RemoteRendererBufferLimitTest.cs b/src/Components/test/E2ETest/ServerExecutionTests/RemoteRendererBufferLimitTest.cs
index 375b386ff577..53ed5dc39e63 100644
--- a/src/Components/test/E2ETest/ServerExecutionTests/RemoteRendererBufferLimitTest.cs
+++ b/src/Components/test/E2ETest/ServerExecutionTests/RemoteRendererBufferLimitTest.cs
@@ -22,7 +22,7 @@ public RemoteRendererBufferLimitTest(BasicTestAppServerSiteFixture<ServerStartup
         {
         }
 
-        [Fact]
+        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/19666")]
         public async Task DispatchedEventsWillKeepBeingProcessed_ButUpdatedWillBeDelayedUntilARenderIsAcknowledged()
         {
             // Arrange
diff --git a/src/Components/test/E2ETest/ServerExecutionTests/ServerInteropTestDefaultExceptionsBehavior.cs b/src/Components/test/E2ETest/ServerExecutionTests/ServerInteropTestDefaultExceptionsBehavior.cs
index 2ba799a3bb9c..73baa0e75f06 100644
--- a/src/Components/test/E2ETest/ServerExecutionTests/ServerInteropTestDefaultExceptionsBehavior.cs
+++ b/src/Components/test/E2ETest/ServerExecutionTests/ServerInteropTestDefaultExceptionsBehavior.cs
@@ -63,8 +63,8 @@ public void DotNetExceptionDetailsAreNotLoggedByDefault()
             }
 
             string GetExpectedMessage(string method) =>
-                $"\"There was an exception invoking '{method}' on assembly 'BasicTestApp'. For more details turn on " +
-                $"detailed exceptions in '{typeof(CircuitOptions).Name}.{nameof(CircuitOptions.DetailedErrors)}'\"";
+                "\"There was an exception invoking '" + method + "' on assembly 'BasicTestApp'. For more details turn on " +
+                "detailed exceptions in '" + typeof(CircuitOptions).Name + "." + nameof(CircuitOptions.DetailedErrors) + "'\"";
         }
     }
 }
diff --git a/src/Components/test/E2ETest/Tests/BindTest.cs b/src/Components/test/E2ETest/Tests/BindTest.cs
index 50b871d01202..54abec28e8c7 100644
--- a/src/Components/test/E2ETest/Tests/BindTest.cs
+++ b/src/Components/test/E2ETest/Tests/BindTest.cs
@@ -2022,9 +2022,9 @@ private void ApplyInputValue(string cssSelector, string value)
             // interaction as authentically as SendKeys in other cases.
             var javascript = (IJavaScriptExecutor)Browser;
             javascript.ExecuteScript(
-                $"var elem = document.querySelector('{cssSelector}');"
-                + $"elem.value = '{value}';"
-                + "elem.dispatchEvent(new KeyboardEvent('change'));");
+                $"document.querySelector('{cssSelector}').value = '{value}'");
+            javascript.ExecuteScript(
+                $"document.querySelector('{cssSelector}').dispatchEvent(new KeyboardEvent('change'));");
         }
     }
 }
diff --git a/src/Components/test/E2ETest/Tests/ComponentRenderingTestBase.cs b/src/Components/test/E2ETest/Tests/ComponentRenderingTestBase.cs
index b4086d1941f6..6bd25034562a 100644
--- a/src/Components/test/E2ETest/Tests/ComponentRenderingTestBase.cs
+++ b/src/Components/test/E2ETest/Tests/ComponentRenderingTestBase.cs
@@ -320,7 +320,7 @@ public void CanUseViewImportsHierarchically()
                 elem => Assert.Equal(typeof(AssemblyHashAlgorithm).FullName, elem.Text));
         }
 
-        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/34679")]
+        [Fact]
         public void CanUseComponentAndStaticContentFromExternalNuGetPackage()
         {
             var appElement = Browser.MountTestComponent<ExternalContentPackage>();
@@ -463,7 +463,7 @@ public void CanUseFocusExtensionToFocusElementPreventScroll()
             string getFocusedElementId() => Browser.SwitchTo().ActiveElement().GetAttribute("id");
 
             // A local helper that gets window.PageYOffset
-            long getPageYOffset() => (long)((IJavaScriptExecutor)Browser).ExecuteScript("return window.pageYOffset");
+            long getPageYOffset() => (long)((IJavaScriptExecutor)Browser).ExecuteScript("return Math.round(window.pageYOffset)");
         }
 
         [Theory]
@@ -725,7 +725,7 @@ public void CanPatchRenderTreeToMatchLatestDOMState()
             });
         }
 
-        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/34857")]
+        [Fact]
         public void CanHandleClearedChild()
         {
             var appElement = Browser.MountTestComponent<ContentEditable>();
diff --git a/src/Components/test/E2ETest/Tests/EventBubblingTest.cs b/src/Components/test/E2ETest/Tests/EventBubblingTest.cs
index 115c0faf170f..d902cfc054be 100644
--- a/src/Components/test/E2ETest/Tests/EventBubblingTest.cs
+++ b/src/Components/test/E2ETest/Tests/EventBubblingTest.cs
@@ -201,9 +201,9 @@ private void TriggerCustomBubblingEvent(string elementId, string eventName)
         {
             var jsExecutor = (IJavaScriptExecutor)Browser;
             jsExecutor.ExecuteScript(
-                $"document.getElementById('{elementId}').dispatchEvent(" +
-                $"    new Event('{eventName}', {{ bubbles: true }})" +
-                $")");
+                $"window.testelem = document.getElementById('{elementId}')");
+            jsExecutor.ExecuteScript(
+                $"window.testelem.dispatchEvent(new Event('{eventName}', {{ bubbles: true }}))");
         }
     }
 }
diff --git a/src/Components/test/E2ETest/Tests/FormsTest.cs b/src/Components/test/E2ETest/Tests/FormsTest.cs
index 050049982e2e..d1bbdf36f910 100644
--- a/src/Components/test/E2ETest/Tests/FormsTest.cs
+++ b/src/Components/test/E2ETest/Tests/FormsTest.cs
@@ -739,16 +739,15 @@ public void RespectsCustomFieldCssClassProvider()
             Browser.Equal("modified invalid-socks", () => socksInput.GetAttribute("class"));
         }
 
-        [Fact(Skip = "https://github.com/dotnet/aspnetcore/issues/34857")]
+        [Fact]
         public void NavigateOnSubmitWorks()
         {
             var app = Browser.MountTestComponent<NavigateOnSubmit>();
             var input = app.FindElement(By.Id("text-input"));
 
-            input.SendKeys("Enter");
+            input.SendKeys(Keys.Enter);
 
-            var log = Browser.Manage().Logs.GetLog(LogType.Browser);
-            Assert.DoesNotContain(log, entry => entry.Level == LogLevel.Severe);
+            Browser.Equal("Choose...", () => Browser.WaitUntilTestSelectorReady().SelectedOption.Text);
         }
 
         [Fact]
@@ -809,9 +808,9 @@ private void ApplyInvalidInputDateValue(string cssSelector, string invalidValue)
             // interaction as authentically as SendKeys in other cases.
             var javascript = (IJavaScriptExecutor)Browser;
             javascript.ExecuteScript(
-                $"var elem = document.querySelector('{cssSelector}');"
-                + $"elem.value = {JsonSerializer.Serialize(invalidValue, TestJsonSerializerOptionsProvider.Options)};"
-                + "elem.dispatchEvent(new KeyboardEvent('change'));");
+                $"document.querySelector('{cssSelector}').value = {JsonSerializer.Serialize(invalidValue, TestJsonSerializerOptionsProvider.Options)}");
+            javascript.ExecuteScript(
+                $"document.querySelector('{cssSelector}').dispatchEvent(new KeyboardEvent('change'))");
         }
 
         private void EnsureAttributeRendering(IWebElement element, string attributeName, bool shouldBeRendered = true)
diff --git a/src/Components/test/E2ETest/Tests/HeadModificationTest.cs b/src/Components/test/E2ETest/Tests/HeadModificationTest.cs
index 2ec264f99633..a98182e8bad5 100644
--- a/src/Components/test/E2ETest/Tests/HeadModificationTest.cs
+++ b/src/Components/test/E2ETest/Tests/HeadModificationTest.cs
@@ -10,7 +10,7 @@
 using Xunit;
 using Xunit.Abstractions;
 
-namespace Microsoft.AspNetCore.Components.E2ETests.Tests
+namespace Microsoft.AspNetCore.Components.E2ETest.Tests
 {
     public class HeadModificationTest : ServerTestBase<ToggleExecutionModeServerFixture<Program>>
     {
diff --git a/src/Components/test/E2ETest/Tests/WebAssemblyAuthenticationTests.cs b/src/Components/test/E2ETest/Tests/WebAssemblyAuthenticationTests.cs
index b59e11be7812..5bb5d369e507 100644
--- a/src/Components/test/E2ETest/Tests/WebAssemblyAuthenticationTests.cs
+++ b/src/Components/test/E2ETest/Tests/WebAssemblyAuthenticationTests.cs
@@ -207,8 +207,10 @@ public void AuthenticatedUser_ProfileIncludesDetails_And_AccessToken()
             },
             payload.Scopes.OrderBy(id => id));
 
-            var currentTime = DateTimeOffset.Parse(Browser.Exists(By.Id("current-time")).Text, CultureInfo.InvariantCulture);
-            var tokenExpiration = DateTimeOffset.Parse(Browser.Exists(By.Id("access-token-expires")).Text, CultureInfo.InvariantCulture);
+            // The browser formats the text using the current language, so the following parsing relies on
+            // the server being set to an equivalent culture. This should be true in our test scenarios.
+            var currentTime = DateTimeOffset.Parse(Browser.Exists(By.Id("current-time")).Text, CultureInfo.CurrentCulture);
+            var tokenExpiration = DateTimeOffset.Parse(Browser.Exists(By.Id("access-token-expires")).Text, CultureInfo.CurrentCulture);
             Assert.True(currentTime.AddMinutes(50) < tokenExpiration);
             Assert.True(currentTime.AddMinutes(60) >= tokenExpiration);
         }
diff --git a/src/Components/test/E2ETest/xunit.runner.json b/src/Components/test/E2ETest/xunit.runner.json
index baa05fb93d2a..d9125313856e 100644
--- a/src/Components/test/E2ETest/xunit.runner.json
+++ b/src/Components/test/E2ETest/xunit.runner.json
@@ -1,7 +1,6 @@
 {
-  // This is set to -1 to allow the usage of an
-  // unlimited ammount of threads.
-  "maxParallelThreads": -1,
   "diagnosticMessages": true,
-  "longRunningTestSeconds": 30
+  "longRunningTestSeconds": 30,
+  "parallelizeAssembly": false,
+  "parallelizeTestCollections": false
 }
diff --git a/src/Components/test/testassets/BasicTestApp/BasicTestApp.csproj b/src/Components/test/testassets/BasicTestApp/BasicTestApp.csproj
index 3033eb876c55..476107e41440 100644
--- a/src/Components/test/testassets/BasicTestApp/BasicTestApp.csproj
+++ b/src/Components/test/testassets/BasicTestApp/BasicTestApp.csproj
@@ -14,8 +14,6 @@
   </PropertyGroup>
 
   <PropertyGroup Condition="'$(TestTrimmedApps)' == 'true'">
-    <StaticWebAssetBasePath>/subdir</StaticWebAssetBasePath>
-
     <!-- Avoid spending time brotli compression publish output.-->
     <_BlazorBrotliCompressionLevel>NoCompression</_BlazorBrotliCompressionLevel>
   </PropertyGroup>
diff --git a/src/Components/test/testassets/BasicTestApp/BindCasesComponent.razor b/src/Components/test/testassets/BasicTestApp/BindCasesComponent.razor
index d0bb9b8c81e8..2b04292aeec9 100644
--- a/src/Components/test/testassets/BasicTestApp/BindCasesComponent.razor
+++ b/src/Components/test/testassets/BasicTestApp/BindCasesComponent.razor
@@ -167,12 +167,6 @@
     <span id="textbox-datetime-format-value">@textboxDateTimeFormatValue</span>
     <input id="textbox-datetime-format-mirror" @bind="textboxDateTimeFormatValue" readonly />
 </p>
-<p>
-    DateTime (format):
-    <input id="textbox-datetime-format-invalid" @bind="textboxDateTimeFormatValue" type="text" @bind:format="MM-dd" />
-    <span id="textbox-datetime-format-invalid-value">@textboxDateTimeFormatValue</span>
-    <input id="textbox-datetime-format-invalid-mirror" @bind="textboxDateTimeFormatValue" readonly />
-</p>
 <p>
     DateTime (format / invalid value):
     <input id="textbox-datetime-format-invalid" @bind-value="textboxDateTimeFormatInvalidValue" type="text" @bind-value:format="MM-dd" />
diff --git a/src/Components/test/testassets/TestServer/Controllers/CultureController.cs b/src/Components/test/testassets/TestServer/Controllers/CultureController.cs
index 735191d92863..93f02a1f7ea8 100644
--- a/src/Components/test/testassets/TestServer/Controllers/CultureController.cs
+++ b/src/Components/test/testassets/TestServer/Controllers/CultureController.cs
@@ -22,8 +22,8 @@ public IActionResult SetCulture(string culture, string redirectUri)
             }
 
             var htmlEncoder = HtmlEncoder.Default;
-            var html = $"<h1>Culture has been changed to {htmlEncoder.Encode(culture)}</h1>" +
-                $"<a class='return-from-culture-setter' href='{htmlEncoder.Encode(redirectUri)}'>Return to previous page</a>";
+            var html = "<h1>Culture has been changed to " + htmlEncoder.Encode(culture) + "</h1>" +
+                "<a class='return-from-culture-setter' href='" + htmlEncoder.Encode(redirectUri) + "'>Return to previous page</a>";
             return Content(html, "text/html");
         }
     }
diff --git a/src/Components/test/testassets/TestServer/Pages/Transports.cshtml b/src/Components/test/testassets/TestServer/Pages/Transports.cshtml
index 6bf003a7b693..2476db63eb8b 100644
--- a/src/Components/test/testassets/TestServer/Pages/Transports.cshtml
+++ b/src/Components/test/testassets/TestServer/Pages/Transports.cshtml
@@ -1,6 +1,13 @@
 @page
 @addTagHelper "*, Microsoft.AspNetCore.Mvc.TagHelpers"
 
+<!DOCTYPE html>
+<html>
+<head>
+    <base href="~/" />
+</head>
+<body>
+
 <root><component type="typeof(BasicTestApp.Index)" render-mode="Server" /></root>
 
 <div id="blazor-error-ui">
@@ -58,3 +65,5 @@
         });
     }
 </script>
+</body>
+</html>
diff --git a/src/Shared/E2ETesting/BrowserFixture.cs b/src/Shared/E2ETesting/BrowserFixture.cs
index 6f1729619697..6911226e5578 100644
--- a/src/Shared/E2ETesting/BrowserFixture.cs
+++ b/src/Shared/E2ETesting/BrowserFixture.cs
@@ -35,6 +35,8 @@ public BrowserFixture(IMessageSink diagnosticsMessageSink)
 
         public string UserProfileDir { get; private set; }
 
+        public bool EnsureNotHeadless { get; set; }
+
         public static void EnforceSupportedConfigurations()
         {
             // Do not change the current platform support without explicit approval.
@@ -143,7 +145,8 @@ private async Task DeleteBrowserUserProfileDirectoriesAsync()
             // Force language to english for tests
             opts.AddUserProfilePreference("intl.accept_languages", "en");
 
-            if (!Debugger.IsAttached &&
+            if (!EnsureNotHeadless &&
+                !Debugger.IsAttached &&
                 !string.Equals(Environment.GetEnvironmentVariable("E2E_TEST_VISIBLE"), "true", StringComparison.OrdinalIgnoreCase))
             {
                 opts.AddArgument("--headless");