It's such a major problem that it wipes out your entire server. So the Plex team still hasn't fixed the issue. Unfortunately it looks like this problem has been going on for months. It was just 30 Minutes later I went to Plex settings to turn it on and I'm like wait a minute where is the turn on server setting and I'm like what's it's gone. Like I was thinking oh the files aren't playing today maybe I should give the server a break and turn it off for now. I'm only reading this post because it just happened to me as well. Tldr I had the same issue, tried a lot of things without success,wouldnt restore my backup, figured its a bug, started over and won't be turning off my server again I will not dare to stop the server because I'm afraid I wont be able to turn it back on if I do. I lost my collections and custom posters but I guess that isnt too big of a deal. (I also can't delete collections but thats another issue.) I didnt want to wait for an update that may or may not solve the problem so I ended up starting from scratch and creating a new server and new libraries. I concluded that there must be a bug in the current version of the plex media server application. The first time it worked but the second time the options disappeared once again. By starting fresh on the plex app I could create a new server but when i copied over my backup data, the pms options disappeared again! I made a test library and tried to stop and start the server. I then tried everything: clear cache, uninstall updates, factory reset the shield, etc. I copied all of my data from the backup folder as well as the android com folder (cant remember the exact name).

When i returned to plex to start up again the option was missing like in your pic. I stopped pms because i was upgrading the hard drives in my nas.

Plex media server nvidia shield