I have been having the same issue for months and even tried factory resetting my TV - for some reason when I go to Live TV > Guide on my android tv and scroll a few lines the plex app either freezes or the app crashes and restarts entirely.
The only fix I have found is to revert to an old v8.0 of the plex android TV app the current version (I have also tried the latest beta) just crash making it impossible to watch live TV unless I cast it.
I have been trying to fix for months and have come to the end of my tether with it so I thought a post here might find some answers!
Has anyone else had this? I have seen a few posts floating on here and reddit but none with any solutions.
Thank you
Latest plex app (and all version 9+ ) on a phillips android tv running android TV 8.0