Minecraft Version: 1.16.5
Forge Version: 36.2.20
Mod Version: 1.0.9
Single Player or Server: Single Player (Skyfactory One)

Describe problem (what you were doing; what happened; what should have happened):
Playing before March 10 I was using a Mojang account, March 9 I died in the Nether, creating a tombstone.
Logging in today, after migrating to a Microsoft account, it's not possible to recover the items as the account has now changed.
The grave appears to be associated with the Mojang account user and not the new Minecraft account.

This also only appears to be an issue for the few that died before migrating an account, something I put off until I was forced to right at the end.

This is not an issue with the mod, but it would be nice to have a flag or admin command to unlock/change the users associated with a gravestone.