GUI hangs up after 'Update Camera'

[SHilgers]

After clicking 'Update Camera' the GUI hangs up. Only Keyboard Interrupt closes the GUI with the error message:

Traceback (most recent call last):
  File "/usr/lib/python3.10/tkinter/__init__.py", line 1921, in __call__
    return self.func(*args)
  File "/home/lab/PycharmProjects/cam/lcg/gui.py", line 1142, in update_settings
    self.video_thread.join()
  File "/usr/lib/python3.10/threading.py", line 1096, in join
    self._wait_for_tstate_lock()
  File "/usr/lib/python3.10/threading.py", line 1116, in _wait_for_tstate_lock
    if lock.acquire(block, timeout):
KeyboardInterrupt