The users logging in are already promoted as editors or authors. But /wp-admin still provides a login prompt for them. I see that when you login through the login prompt at /wp-admin, you are provided a new cookie. I can’t seem to find anywhere to set this new cookie.
Problem is – these users are not supposed to have admin rights.
The ones that needs auto-auth trough wp-admin are editors and authors.
But thank you for the suggestion.