4K won't direct play smoothly on 2017 nVidia Shield Pro anymore

For movies with TrueHD audio, there are issues with the Shield. Try choosing the Dolby Digital / AC3 track if available. There are other threads regarding overall stability problems with the Android TV app. Hopefully Plex will get the kinks worked out soon.

Plex DocumentationAndroid TV, FireTV, & PortalAndroid TV, FireTV, & Portal Logs.