A couple of days ago, I was messing around in the Hogwarts Map I've been working on when I noticed that when using the /function command, the functions are not there, even though the datapack is there.

Steps to Reproduce:

1. Download Map (Skip if you have done so): https://www.planetminecraft.com/project/mrkaspersson-s-hogwarts-map-ultimate-continuation-no-download/
2. Run Snapshot 20w09a or later
3. Load that map
4. Try using /function

All functions disappear. This can be fixed temporarily by disabling one of the datapacks and then re-enabling it (not the vanilla datapack)