USB camera (Logitech) stops working until reconnected
As commented, I have a similar issue on Windows 10.
I recently noticed a warning in logs mentionning that I was using the webcam with a 2.0 USB port (the only one left available on the computer). I switched to a 3.2 USB port, and no disconnection since more than one hour... I read at several places (like here) that the webcam only works as expected in 4K with the default / logitech cable or a full compatible one, which would need to be USB3 480mbs at least. So plugging it in a USB2 could indeed be problematic. As you use -r 4096x2160, you problem could be identical ?