My Watch History and Movies/Shows/Episodes Counts Stopped Updating

I’ve been trying to have a little fun and run my Movies, Shows and Episodes counts up by watching a bunch of new stuff, but they suddenly stopped updating.
I can mark something as watched, but the numbers don’t increase and it doesn’t add anything I’ve watched to My Watch History.

I’ve toggled Sync My Watch State and State off/on and that hasn’t fixed it.

It doesn’t matter if I mark something watched from the iPhone app, AppleTV or the webpage.

Update: It looks like it’s only things I watch from my friend’s server and not hosted by Plex.