Plex app won't play content; Plex web app will.

I’m having an issue for a few weeks getting the Plex app on Android to play videos from my PMS (nvidia Shield TV). All versions of the app I’ve tried have failed (Phone, Android TV, app running on Pixelbook). Not only does playback not happen, but the app usually craps out completely, offering to restart or send feedback (which I have several times).

As the title says, I can view the videos if I use the Plex web interface.

I posted in the nvidia PMS section but didn’t get any suggestions, so I’m casting a wider net.

Thanks.

I would love to share some Plex logs to someone who is interested in helping me track down the issue.