DAX coalesce function consumes all available memory

Ok, vgeldbr - see if this helps. I think this is a modeling problem. Your aggregate status was another table in a 1:Many relationship with the Engagement Codes table, and the latter wasn't filtering the former.

I could have worked on some DAX to do some crossfiltering, but that is more complex than it needs to be. The Aggregate status is really just a lookup table it seems, so I just merged it into the Engagement table. You can see my results in the lower right.

This is a super simple measure.

Actuals = 
VAR varActualCount = COUNTROWS(Actuals)
RETURN
IF(
    ISBLANK(varActualCount),
    0,
    SUM(Actuals[ExpenseUSDCurrentFYTD])
)

If there are no rows in the Actuals for a given code, return zero, otherwise the total. At this point, your dim_engagement codes doesn't even need to be loaded. Use your Engagement codes as the DIM table and the Actuals as a FACT table - a perfect Star Schema. See my PBIX file here. Look at the merge I did in Power Query.

Microsoft Guidance on Importance of Star Schema