DAX Help - Prior year rolling total

HI FletchNZ,

I think it may related to filter conflict between different time intelligence functions.

Time Intelligence in Power BI Desktop

Optimizing DAX expressions involving multiple measures

If this is a case, I'd like to suggest you manually point out date range which dax formula calculate instead to nested multiple measures with specific filters.

Sample:

12M Total Service Request :=
VAR currDate =
    MAX ( 'Date'[Date] )
RETURN
    CALCULATE (
        [Total Service Request],
        FILTER (
            ALLSELECTED ( 'Date' ),
            [Date]
                >= DATE ( YEAR ( currDate )-1, MONTH ( currDate ), DAY ( currDate ) )
                && [Date] <= currDate
        )
    )

Prev 12M Total Service Request :=
VAR currDate =
    MAX ( 'Date'[Date] )
RETURN
    CALCULATE (
        [Total Service Request],
        FILTER (
            ALLSELECTED ( 'Date' ),
            [Date]
                >= DATE ( YEAR ( currDate ) - 2, MONTH ( currDate ), DAY ( currDate ) )
                && [Date]
                    <= DATE ( YEAR ( currDate ) - 1, MONTH ( currDate ), DAY ( currDate ) )
        )
    )

Regards,

Xiaoxin Sheng