We use external groups for authentication and handling permissions. Therefore we do not use "Anonymous" or "Authenticated Users" (they have 0 permissions). However on folder level those groups are still available to the users. This results in confusion as when they give these groups permissions, nothing happens.
       

If an admin creates a group on global level, it does not "magically" appear on folder level as "Anonymous" and "Authenticated Users" does. The newly created group needs to be manually added on folder level by the user to be able to grant permissions.

Only groups(pre-existing or created by admins on global-level) that have permissions should be visable in projects/folders.