If a group administrator has permissions in their access level lower than those they manage, they will not be able to view, modify, or assign lower access levels.
Problem
If a group administrator is assigned a modified Planner access level with View permissions for Teams, but certain users are assigned a Worker access level with Edit permissions for Teams, the group administrator will not be able to interact with the modified Worker access level.
NOTE
This logic also applies to the Fine-tune your settings drop-down menu. Both access levels can have Edit access, but settings in the Fine-tune your settings drop-down menu must be higher for the group admin.
Solution
Group admins must have higher permissions in all areas in the access level than those they manage.
