Try turning off commercial detection.
This is in Plex Media Server.1.log immediately prior to the crash (at least on 3/11, /12, & /13):
Mar 11, 2022 21:03:33.471 [0x70000a1d7000] DEBUG - Jobs: '/Applications/Plex Media Server.app/Contents/MacOS/Plex Commercial Skipper' exit code for process 8744 is 0 (Commercials found)
It seems to line up with this thread, where the ad detector is crashing: Plex crashing while watching.
