How to sum the aggregated values visible in Matrix visual

Hello,

I'm new to using DAX.  I have two tables that share a many to many relationship with cross filter direction of both. They are joined on a column called "Equipment"

I'm using a matrix table that has column data grouped/rolled up(Contract # (groups). I also have a measure that shows the correct values when you drill down(Miles). Table "TableAContract" has a grouped/rolled up "(Contract # (groups)". Table "TableBMiles" has the measure(Miles) as the "Value".   When I drill down I can see the sum of the rows visible in the matrix visual. The total shows the correct expected sum of the visible aggregated values.  

However if I drill back up to (Contract # (groups) the sum of the aggregated values visible in the matrix visual is not displaying those visible values in the column as a sum.  (My columns are grouped/bins of a date).

I would simply like the subtotals at the top level(s) to sum the visible values.  I've read that SUMX and SUMMARIZE can help with that but unsure how that works.

Please help

Thank you