Thanks for reporting this. If it is easily reproducible, could you please enable debug logging on the server - see https://support.plex.tv/articles/201643703-reporting-issues-with-plex-media-server/
and restart the server and when the problem appears again, please collect the logs zip and attach here
See https://support.plex.tv/articles/200250417-plex-media-server-log-files/
Do you know what player apps were being used at the time ?
