If anyone wants to try to rollback to the previous version of Plex to try to make the playback working again, the instructions are here: Reddit - Dive into anything
Close Plex.app if it’s running.
Download previous version:
https://downloads.plex.tv/plex-desktop/1.106.0.276-fe8d1d20/macos/Plex-1.106.0.276-fe8d1d20-universal.zip
Copy Plex.app to Applications folder. Do not open Plex.app.
Edit plex.ini file as per: Plex for Mac 1.68.2.3746 Crashes on Launch (High Sierra) - #7 by FordGuy61
Essentially edit ~/Library/Application Support/Plex/plex.ini with the following to disable auto updates:
[debug] <-- add debug section if it does not exist.
disableUpdater=true
