Thread continues to run after game quits

I start a server on a different thread, and things seem to go fine while I'm running my game.

But if I run my game a second time after I exit play mode, Unity freezes.

When I comment out the last line (serverThread.Start()) in the following code, I no longer have this issue.

 using System.IO.Pipes;
 using System.Threading;

 // ...

 public static void SomeFunction() {
      // ...
      serverThread = new Thread(new ThreadStart(() => {

             NamedPipeServerStream pipeServer = new NamedPipeServerStream("testpipe",
                    PipeDirection.InOut, 1, PipeTransmissionMode.Byte);

             pipeServer.WaitForConnection();
             // ...
             // some more stuff that should never be reached
             // because client is not yet open
             // ...
      }));
 
      serverThread.Start();
 }

I also tried calling Thread.Abort() on serverThread immediately after starting it (i.e. the next line), but this had no effect.

How can I avoid this situation? Is there a different, safer way to call make a blocking call? Is there a way to abort my thread at some point before exiting that will actually work?