OK gotcha - the Python version of videoSource.Capture() only returns an image, or an exception if a timeout occurred.
Unfortunately I’m unable to debug what is the exact issue here (and I’m by no means an expert on Python multithreading). Does it change the behavior if you increase the number of buffers in the videoSource/videoOutput with the --num-buffers argument (the default is 4)? Or you can change it here and recompile/reinstall - this would be useful to know if it’s related to the problem.