I have narrowed my problem down to the many to many relationship between user and group record types. When a user transfers ownership of a group the new admin can change things like privacy (a field) but still only the original owner can leave or remove others. The new admin's use of remove user does nothing and no users can leave besides the creator. All security perms are enabled, and no permission not granted errors arise. I simply end up with two unsynced devices where one user observes themselves as having left, and the other that never will observe it. I can get around this a long way but don't really see why I should have to.