I managed to fix this!
What didn’t work:
- Restarting the Roku
- Power-cycling the Roku
- Restarting the Plex app
- Uninstalling the Plex app, rebooting, and reinstalling the Plex app
What did work:
- Factory resetting the Roku Ultra.
This was the nuclear option and I don’t quite understand why it worked when reinstalling the app didn’t. A complete system reset was annoying, but apparently necessary.
I hope this is helpful for others in the future.
Side note: The factory reset also fixed a consistent MPEG2 playback crash I had reported a few weeks ago.
