Are your own libraries configured to use the new Plex metadata agents,
and have the libraries completed a “Refresh Metadata” run after changing that setting?
https://support.plex.tv/articles/upgrading-a-movie-library-to-the-use-the-new-plex-movie-agent/
https://support.plex.tv/articles/migrating-a-tv-library-to-use-the-new-plex-tv-series-agent-scanner/
If not, you can’t expect your own media to show up in the Watchlist.
https://support.plex.tv/articles/universal-watchlist/
