[msh]

If you only have apple clients (iOS, ipadOS, tvOS and macOS) you can try infuse. Its only a client, so you need to store your files somewhere (icloud, gdrive, you NAS) but it can then play all kinds of files and sync progress between different instances of it self. If you dont want transcoding on the server and only uses apple devices for playback it IMHO works much much better than real plex.

It can also play at being a plex client to provide better playback options than the official plex app.

[nerdjon]

Maybe infuse is different if not pointed at jellyfin but that was the client that would have issues with my library. It would loose its cache or something, I don't remember now, all the time.

[msh]

I have run infuse for a few years first against Plex and then files on GDrive. I have not encountered that problem.