Matrix Group By Excludes Last Value

I have a Matrix that counts records by one group. In a simplified scenario, the group values are 1, 2, and 3. When I created the matrix without a subtotal, all 3 groups are returned. I added the subtotal column, and now only 2 of the groups are returned. The dataset query looks like this:
SELECT A

, B
FROM Table

Without Subtotal this is returned:
A CountOfB
1 3
2 6
3 7

With Subtotal this is returned:
A CountOfB Subtotal
1 3 3
2 6 6


The last value is missing. When I remove the subtotal column, the last value does not return. Where did it go? Am I missing a setting?


Thank you so much for reading this. Any help would be appreciated.
babs