Are you using a bluetooth headset or similar? Something that goes to “sleep” after a time? Once the F/O’s audio device is “lost” it won’t come back without a restart of the flight session.
There's a beta version you can try: https://forums.x-plane.org/forums/topic/338565-x-camera-245-beta/
There's also reports of issues when using Tobii and 12.4.
But without a Log.txt from X-Plane we can't really help further.