Per Customer YTD Totals in Matrix Incorrect

Hi All,

I am having an issue with my YTD measure excluding specific customers from my matrix.

The subtotals for each month are correct, however when I expand it to look at YTD values per customer I find that some customers are missing if they have zero activity for that specific month. For example, customer Seven Corners had activity of $14,000 in 8-2022. However, this amount is not included in 2022-09, 2022-10, or 2022-11 when the matrix is expanded (I assume due to row context).

The measure I am using to calculate the YTD values is: 

Year-to-Date Margin = TOTALYTD(SUM('MH History Detail'[Margin $]), 'MH History Detail'[Month Ref])

Is there a way to rewrite my DAX formula so that customers such as Seven Corners will have their YTD values included even in months where they have no specific activity? In other words, so that Seven Corners will have a value of $14,000 in month refs 2022-09, 2022-10, and 2022-11?

Thank you in advance!