Update

Author: JamesNK

src/Servers/Kestrel/Transport.NamedPipes/src/Internal/NamedPipeConnectionListener.cs

@@ -65,7 +65,7 @@ public void Start()
             // Start first stream inline to catch creation errors.
             var initialStream = CreateServerStream();
 
-            _listeningTasks[i] = StartAsync(initialStream, i);
+            _listeningTasks[i] = Task.Run(() => StartAsync(initialStream, i));
         }
     }
 

src/Servers/Kestrel/Transport.NamedPipes/src/NamedPipeTransportOptions.cs

@@ -14,7 +14,7 @@ public sealed class NamedPipeTransportOptions
     /// <summary>
     /// 
     /// </summary>
-    public int AcceptQueueCount { get; set; } = Math.Clamp(Environment.ProcessorCount, 1, 16);
+    public int AcceptQueueCount { get; set; } = Math.Min(Environment.ProcessorCount, 16);
 
     /// <summary>
     /// Gets or sets the maximum unconsumed incoming bytes the transport will buffer.

src/Servers/Kestrel/Transport.NamedPipes/test/NamedPipeConnectionListenerTests.cs

@@ -77,16 +77,15 @@ public async Task AcceptAsync_ParallelConnections_ClientConnectionsSuccessfullyA
 
         var currentCallCount = 0;
         var options = new NamedPipeTransportOptions();
-        options.AcceptQueueCount = 16;
+        options.AcceptQueueCount = 1;
         await using var connectionListener = await NamedPipeTestHelpers.CreateConnectionListenerFactory(LoggerFactory, options: options);
 
         // Act
         var serverTask = Task.Run(async () =>
         {
             while (currentCallCount < TotalCallCount)
             {
-                var connection = await connectionListener.AcceptAsync().DefaultTimeout();
-                await connection.DisposeAsync();
+                _ = await connectionListener.AcceptAsync();
 
                 currentCallCount++;
 
@@ -110,7 +109,7 @@ public async Task AcceptAsync_ParallelConnections_ClientConnectionsSuccessfullyA
                         await clientStream.ConnectAsync();
 
                         await clientStream.WriteAsync(new byte[1]);
-                        await clientStream.ReadAsync(new byte[1]);
+                        await clientStream.DisposeAsync();
                         clientStreamCount++;
                     }
                     catch (IOException ex)