Apparently, it has been fixed in the latest Andriod TV - Beta released today. I've not had chance to verify though....
Plex for Android 188.8.131.524-beta
Available on Google Play
Support for timeshifting Live TV programs (requires PMS 1.8+).
Include Afrikaans translations.
App was failing to persist library filters selection after being closed.
Don't switch to 'Open Video File' section when Local Server selected if synced content exists.
Local Playback: disable External Player for Local files.
[Android TV] Chapters would not always show.