You can disable auto updates and side load 8.28.0 (if you don’t want to use Kodi) for now until they fix this - that version still works for me for AAC passthrough.
I posted this problem as well the 26th of January.
https://forums.plex.tv/t/version-8-29-broke-aac-passthrough/772996
Question: Which passthrough method do you normally use? HDMI or Optical?
