Nvidia released the first Shield Android TV boxes back in 2015, and it's still updating them in 2022. The various generations of Shield just recently saw an update to Android 11, but owners have reported numerous apps, including the device's built-in Plex server, have stopped functioning. Nvidia is still working on a patch for the software, but you can (probably) get it fixed now if you're impatient.

The Shield Experience 9.0 update bumped the device to Android 11 (skipping Android 10 entirely). You might recall from last year that Android 11 added scoped storage to the platform, which limits the directories apps are allowed to access. This is good for privacy, but it can break apps. Users report issues with Plex, Kodi, HomeAssistant, VLC, Netflix, and others. It's not clear if all the issues are due to scoped storage, but we can confirm the Plex dysfunction does relate to this change.

SHIELD_TV_Experience_9.0

According to Nvidia, Plex was tested and working during the beta period, but Plex pushed a new version of Plex Media Server (PMS) to the store before the rollout that changed the reported API level. This broke PMS on the final version of the software. If you don't want to wait for the new patch, you can request early access to a hotfix. Simply fill out Nvidia's form with your device's serial number, and you'll get an OTA. You might also have to manually install the latest Plex Media Server APK, which is available direct from Plex. For other apps, manually allowing file access in the settings might help.

For the record, I have two Shield boxes, and both have been updated to Android 11. I don't run a Plex server on the box anymore, so I can't comment on that. Most of my apps have been working fine, though. If you're in the same boat, you can just wait for the patch to roll out in the normal course.