I have a set beatmapsets/2331746 which should have ~7 difficulties since last update (8 days ago), and I'm pretty sure it's the case even until yesterday. But when I check it today, somehow only 3 difficulties are shown.

The map is submitted from lazer, if that's relevant.

Can you export the beatmap (from lazer) and it through a file/media sharing website for us to take a look at, and once done can you attach the link to a new reply, make sure that its viewable to all who have the link.

The beatmap export is not necessary. The online .osz has 7 .osu files inside. Something is clearly wrong.

The four difficulties in question appear to have been deleted on 2025-05-27 12:53:47 UTC. We've restored them for you, but this doesn't really explain why this happened.

@OP:

1. Are you sure you did not attempt to update the beatmap within the last day?
2. Are you sure you didn't get any submission errors at any point?
3. Please logs, button to export them is in settings.
4. I notice that on your profile page you have a section with "some lazer tweaks". Did you submit the beatmap from an unmodified and official version of the client?