My expectation is that when you tick an item, whether it's an individual department or a departmental range, the user is granted full access to that department or range. In other words, each item stands on its own.
If it is mandatory that each individual department within a range be ticked for the user to be granted full access to the departmental range, then why bother offering the departmental range box as an option to tick. Ticking it or not ticking it makes no difference. It should show up on the dropdown list only if all of the departments in the range are ticked.
Your scenario is the exact issue that resulted in my posting. A client added a new department and it wasn't showing up in the departmental range report. They didn't expect that they would have to tick the individual department, because the departmental range was already ticked.
Steve