I waited for all that to finish. I tried to help it along by going through everything so it would cache it all. It wasn’t as straightforward as Plex’s visual, flipping covers over as the metadata loads in for each movie, providing a clear queue and sense of progress.
Once on the client side, it felt like those also needed to cache things. The only client that worked semi-well wasn’t a Jellyfin client, but could read from a Jellyfin server. I think it was called InFuse. With that as well, I spent hours simply navigating the app, going to every page, and waiting for it to cache everything so I could then navigate around. Then if I added something new, I needed to go to a page to show it and get it cached.