Nvidia Shield TV 2017 - UHD via Plex Player

None of my UHD media files (.ts, .mkv, .mp4) from NAS or Local USB drive plays in UHD (only 1080p)
Both Plex Server and Player are installed on the same box (NS 2017 ATV running firmware 6.3).
This is better than previously where none of my UHD files played at all, now they play at 1080p (according to the onscreen overlay)

I really had enough of Plex already without stupid stuff like this (Kodi plays the same file just fine, even MXPlayer works)

Is there a fix / workaround? (OR is it another Plex bug i have to live with until they can be bothered to fix it)

I’m having the same problem starting around 3 weeks ago.

-4K HDR Files are taking now lots of time to load
-Video will not be displayed in HDR on the tv
-Audio from Atmos gets modified to DD+
-In cases where i have 2 versions of the same movie (4k and 1080p 3D for example), if i select the 4K one, it would load and after some seconds switch to the 1080p version instead.

All these files up to 3 weeks ago were correctly playing, lunched smoothly, HDR + Atmos correctly processed.

So after a couple of weeks of more searches and try, yesterday finally i was able to fix this (by pure coincidence).
Here is what i did:

-Move the 4K HDR files that are not working from the library’s folder to another one
-Refresh the server, so that the files gets removed from your server
-Move back the files in your library’s folder
-Refresh again the server to load the files back.

Doing this, fixed all my 4K HDR files, including the Atmos one which are now all working too.
No idea why this, but at least for me it solved those issues.

@r4b1d said:
So after a couple of weeks of more searches and try, yesterday finally i was able to fix this (by pure coincidence).
Here is what i did:

-Move the 4K HDR files that are not working from the library’s folder to another one
-Refresh the server, so that the files gets removed from your server
-Move back the files in your library’s folder
-Refresh again the server to load the files back.

Doing this, fixed all my 4K HDR files, including the Atmos one which are now all working too.
No idea why this, but at least for me it solved those issues.

This did not work for me - all 4K files still playing at 1080p.