Through a combination of listening to stuff from Spotify that isn’t in MusicBrainz, and poorly tagged local files, I ended up with quite a few listens in my Missing Data page. I’ve been through and linked them all, but two were duplicate listens created by the Spotify player. I seem to have confused that database by deleting the “wrong” duplicate listen from my Listens data and I’m now stuck with 2 listens in Missing Data that I can’t delete.
I understand that deleting items only adds them to a queue to be later deleted in a batch and I’ve also found an old discussion about it possibly taking 15 days for updates to the Missing Data list to be fully effective. I don’t think I’m hitting either of these as I’ve tried to delete them several times over several days and everything else I’ve done to fix Missing Data has happened instantly - so I think the 15 days thing has been improved significantly!
Edit - they’re gone now. Maybe t he 15 days is still a thing?