07:56:22.434: Max audio buffering reached!
07:56:22.434: adding 975 milliseconds of audio buffering, total audio buffering is now 1044 milliseconds (source: webcam)
I think here is your problem. Whenever the max buffer of one second is hit I think OBS basically gives up. There is something wrong when you reach that so soon. I would try to check disconnecting the webcam or remove all its sources and see if that helps.
EDIT: I would use V4L source for the webcam and not the FMPEG one.