Android TV: Cannot play any video, only audio is being played

Did you try with the most recent version of the Android TV app?
As tautulli tells you it’s direct playing, did you try to force transcoding by reducing the bitrate in the player below the bitrate of the original file?
Does Plex web (dashboard) also say it’s direct playing?

Server logs do not contain senstive data, it is ok to post them.