Another thing you can try is to force (one of ) the measures to use a value from the table containing the 'Department' column. That could also be a dummy number added in data prep (add a column of 1's). Or if your Department names are unique, you can use their distinct count.
So something like <your formula>*MAX(dummy column) or <your formula>*COUNT(department). Both of these should multiply by 1, resulting in the actual value of your formula. But now the formula has a component from your columns table.
Or if you really want to be sure the number doesn't have an *actual* influence: <your formula> + 0*Count(department)