How does automatic sync get triggered?

I’m using Navidrome, and I’ve always just done manual syncs (with the auto sync disabled via the database settings), but I recently got ionotify working on the server side, and thus automatically adding new music to the library when I copy it over. Thought I’d give the auto sync on Symfonium a try as well, but it’s been well over an hour since I added an album to the Navidrome library, and nothing has shown up in Symfonium.

What actually triggers the syncing of new music? It appears that it’s not doing whatever that is from just sitting there with the app open.