Some video content from the server won’t automatically play on the Apple TV beta client. When I notice a video doesn’t start to play, I have to quickly use the top menu within the video to change it from “play original”, to “convert automatically” and then it will play.
Video from the DVR system always plays fine this bug seems to be a transcoder problem on some video file formats.
My system is Apple TV OS 14 beta with plex tv os beta v7.5.1 and plex server beta (all fully updated)