Were having the exact same issue as of yesterday. This logitech camera is a C922C Logitech webcam. I recently installed the latest Mac Logitech webcam drivers (Software version 2.5.12 from logitech website) which improved control and options from within OBS over the MacOs internal driver but now we are getting freezing issues after 2 secs of streaming which didn't happen before. I'm wondering if it might be a power saving feature that needs turning off or a buffering setting for the webcam that's misconfigured or possible bug in the driver? This is after latest Mac Os updates 10.13.6 High Sierra..
Has anyone else had this issue?