The [before] and [after] option hook not allow http POST request?

[DemonCloud]

Operating System: Mac OS 10.15.2
Node Version: 13.5.0
NPM Version: 6.13.4
webpack Version: 4.41.4
webpack-dev-server Version: 3.10.1
Browser: Chrome

! This is a bug

I was writing an express middleware, try to send request dev server, but it not allowed!
** But webpack-dev-server 3.9.0 work fine!!!**

[alexander-akait]

Please create reproducible test repo