Your phone has the old version of the Plex app, 10.26.0.2578. It has not been updated in several months.
The Apple & Android mobile apps were updated in March 2025 to the “New Plex Experience.” Release notes: Plex for Mobile (Android & iOS)
The current version is 2025.30.0.
The Android TV app has not yet been updated to the “New Plex Experience.”
The current version for the Nvidia Shield is 10.30.6.4151 (I just checked my Shield).
Apparently at some point you signed up for beta releases.
PMS v1.43.x is the current beta release. It has an updated transcoder based on FFMPEG 6.1. The current public release, 1.42.x, has a transcoder based on FFMPEG 4.
This page is used to join/leave the beta program for the Plex Android app. I am not sure if it also works for PMS on a Shield: https://play.google.com/apps/testing/com.plexapp.android
