Both of my Sony 4K televisions have lip sync issues when playing content via the Android TV Plex app. I’ve tried using transcoding of both, just one, and Direct Play and the experience is always the same - the audio is up to a full second behind the video.
Playing the same content on the same TV using the “Videos” app and accessing the file via DLNA shows that everything works fine and it is not an issue with the media file itself.
I’d like to propose a Sync Control function in the Plex Apps that will correct for small variances in timing that appear to be directly the “fault” of the processing of the various pieces of the content (audio and video) by the Plex app itself.