Grouped Measure Field Parameters Not Working

Hello! I'm stumped and hoping someone here is smarter than I am!

I created a field parameter with 6 measures and added a 'Group' column that identifies them as either 'Actual' or 'Forecast' measures. I'd like to use the 'Group' as a column header in a matrix, so you'd see the 'actual' measures under 'Actual' and the 'forecast' measures under 'Forecast'. However, when I move Group into the column headers, I get all 6 measures under each group and I can't figure out why. If I select one of the groups from a slicer, it works as expected and only shows the 3 measures in that group. If I don't select anything, it shows all 6 under each group.

Parameter

Matrix (Current State)

My matrix looks like this but I'd expect only the red columns to be visible under 'Actual/Backlog' and only the blue to be visible under 'Plan/Forecast'. As of right now, they are all showing up under both.

Matrix (Expected)

I just made the columns narrow here to show what it should theoretically look like.

Here is how I have the matrix set up.

Any information would be extremely helpful 😁

Thanks