Hi,
Try to confirm if the admincount attribute of the user is still remain one, is yes ,change it back to zero .
When a user / group is removed from a protected group, adminCount attribute value will remain equal to one (1). Also; the owner, ACLs and permission inheritance status (Enabled or Disabled) will remain the same. Change it manually.
Logout and login in again to refresh the group membership.
Best Regards,