I haven’t figured out why yet so I can’t really report this as a bug along with any useful information but I thought if I mention it here that someone else might have had the same problem and know the solution.
I’ve also noticed that the customization of the libraries that I shared with other Plex users gets reverted to default parameters as well. I’m not sure which file this information is stored, if someone knows please let me know.
The only thing I can think of that would cause this different to most people is that I have moved the directory that the Preferences.xml file is in from its default location to a place that is on a large disk. I’ve used the override.conf file method to point to this location so I don’t see why it should be a problem unless there is some subtle bug somewhere in the code that shows up occasionally.
This is on my own workstation, OpenSUSE Leap 15.1.
That said, I might have figured this out. Again, I’m not sure and will have to wait a while to see what happens but I put a symlink from its default /var/lib/… to where I now have that directory and it seems, so far, to have resolved it.
This way if there is the odd occasion when it tries to look at the default location it still gets where I put it.