Sorry for the delay, we are looking into the issue and improving the app’s performance on the SHIELD Tube, sadly we don’t have a magic solution but we are definitely working on it as a high priority!
If you have a SHIELD Tube, you will want to sign up to our beta to ensure you have the latest version of Plex.
Would you able to let me know the media information of the 4K videos that crash your device? I am able to playback 4K on my Tube, but it will crash when the player is terminated.