First rolling back your server that far isn’t going to help with an old TV that has an out of date app.
Second posting snippets of logs like you have doesn’t help anyone to troubleshoot what may be happening, you should always post the full application if possible and server logs in a zip.
Third your problem is almost certainly related to this → Important information about Plex for smart TVs after September 30, 2021 - Announcements - Plex Forum
You can either try the steps described in the post as a workaround, or what I always suggest is invest in either a new Chromecast with Google TV or if you want the best possible option the Nvidia Shield Pro(not the tube though).
