@StuartFlint Start by separating things into variables and you will realize that MAX ( ) isn’t related to the rows iterated by FILTER.
Unless you are using RELATED/RELATEDTABLE/CALCULATE/CALCULATETABLE and time intelligence functions instead of MAX, you can always assume that MAX/MAXX/SUM/SUMX/MINX/AVERAGEX all are evaluated in filter context and not row context.
MAX is getting Filtered here. Just remember this Row context iterates and Filter context filters. The opposite(Filter context iterates and row context filters) of this isn’t true.
