haven’t looked at your logs yet (thanks for attaching them though), but the two main things that cause 4k problems are;
- HD audio … shield needs to be plugged into a receiver that can handle truehd/atmos/dts-hd-ma, otherwise plex will transcode the audio
- if you have subtitles enabled, and audio is transcoding, that will force video to transcode, and then you will lose 4k/hdr
if neither the above is true, ensure that you have shield and plex settings set to hdmi pass through
if you have not already read, see @ [INFO] Plex, 4k, transcoding, and you - aka the rules of 4k for a lot of 4k related info
