QThread with parent and QObject worker blocks main thread

When creating a QThread and connecting slots to a QObject as a "worker" to wrap a function or method, if a parent (in this case a subclass of QMAinWindow) is assigned to the QThread calling QThread.start() blocks the main thread. This issue does not occur with PyQt5. A minimal example is attached to demonstrate this behavior. Changing the line "self.test_thread = create_thread(self.long_running_task, parent=self)" and setting the parent to None fixes the issue.