Ran into the same issue now. Either there have been breaking changes to the account linking behaviour that have not been communicated in any way or it’s flat out broken. I’m using the /api/v2/users/{id}/identities endpoint to link users, not the rule (although I’d imagine the rule uses the same API in the end)
Before after successful account linking the result was one working user with two identities. What happens now is there’s one user with two identities and one seemingly broken user that shows up in some queries but not others.
This broken user shows up in the auth0 users UI, but when you try to open the user you get a User not found error.
This broken user shows up if I search for users via email.raw query with the /api/v2/users endpoint. If I look for the user with /api/v2/users/{id}, the user can not be found. Same thing if I try to delete this “ghost” user. So basically our auth0 database now has some kind of corrupted users that show up in some searches but not others and can not be deleted.