I have this exact same issue. I had been using a Pixel and it worked at least 50% of the time. I would need to go back into the app on occasion and force a refresh and then it would work until next reboot of phone or randomly at some point. Since moving to the OnePlus 8T it works maybe 5% of the time. I have changed battery optimization settings with little luck. I have found the only time it’s successful at uploading pictures is if I launch Plex at least once or twice a day. It seems to sync about 75% of the time when you open the app often enough, but on any reboot you need to manually start the sync again. Very annoying considering I paid for this feature…
I just gave up. I also paid because of this feature but it’s being so flaky that I disabled and started to use DS photo with my synology [1]… It works flawlessly!
Add me as another Android user where this feature has stopped working. If I launch the Plex application and go to camera uploads in settings and click start, then it works just fine, but the automatic uploading doesn’t work. I thought it might be aggressive power management preventing it, but my phone has Plex set to be able to run in the background and I have disabled “adaptive power management” and specifically set Plex to not go to sleep.
I’m also frustrated because I bought a lifetime Plex Pass specifically for the photo uploads and syncing content to devices. both features have NEVER worked reliably. I’m now having to search for other options to manage my camera uploads, but refuse to use Amazon or Google, for my personal data. I mean isn’t that the one of the purposes and reasons given to setup a Plex Server anyway?
Same issues across both a mainline install from the app store on a Pixel 4 XL and a beta version on Pixel 3 XL. Rarely if ever do they automatically upload. I have adjusted power settings to suggested.
What does someone need to troubleshoot this? I will provide anything requested.