Delete User Still shows up in Access Rules?

We deleted a user from our Grist document (Manage Users in document), but the user still shows up in the access rules tab (View Document as, from Access Rules - View As). how do we delete the user from access? It is strange that in the Access Rules the user is still an Editor, but they are no longer an approved user on the document. how is this possible?

One possibility is that the user is still listed in a User Attribute table, is there such a table in the document?