I think you are correct on this. My server is connected to 5 bay external hard drive and have had many power cuts recently that could cause the hard drive to not reboot even if the server does reboot. Then when the plex server runs an update, it deletes the item from my library because it can no longer reach the file. Turning off “auto delete” has solved the issue, but I do have to manually delete every now and again.
This is most prominent for new shows only and only happens on my Android TV. I removed “Lost Ollie” from my library and then ran a scan and trash clean up. I then added “Lost Ollie” back to the file directory folder and scanned again. It picked up Lost Ollie in the album art and even opens up Lost Ollie when I press on the poster, but in the top description at the top third of the screen, it showing as “Days of our Lives” which is the exact description as the days of our lives tile 3 tiles to the right of the screen. This is only for Android TV because only Android TV uses that top third bar description. Another important point is that it is happening on all my Android TV boxes, and not just one in particular.