Issue closing thread

I have encountered an issue closing a thread using the quit() method in the latest pyside2 release (5.15). The issue does not appear in <=5.14.2 and does not appear in PyQt5.

The issue occurs when using the quit method on a thread and then immediately waiting on it. Introducing a delay between the quit() and wait() can avoid the issue suggesting an event loop issue to me.

A workaround is to poll thread.isRunning() and calling QApplication.processEvents() between polls.

I posted about this on Stack Exchange but didn't get any replies so thought it was worth raising here.

I have attached a minimal reproducible example to make the issue clear.