I know it sucks folks, but plex devs are obviously aware.
Plex never did support this tv system, so blaming them for it getting broke when it was never intended to work, is stretching it.
Hopefully they will get the issue ironed out soon, but if you can’t wait the work around is already been stated.
If you don’t have control over your server, then perhaps you should reconsider your hosting.
Finally, this problem should be a wake up call, cause sooner later something else could break and you might just be completely SOL.
Consider a roku or even fire device instead of relying upon an old, unsupported, and insecure client that could stop working at any time.
Peace.
