Sales Summary - Order Demand vs. Forecast Demand

Hi jrhaney23 , yes, Use your dimension tables dCustomer, dMaterial and connect them:

fOrder[Customer] --> dCustomer[Customer]  
fForecast[Customer] --> dCustomer[Customer]  
fOrder[Forecast Material] --> dMaterial[Forecast Material]  
fForecast[Forecast Material] --> dMaterial[Forecast Material]

Use "ALL(dDate)"  instead of "REMOVEFILTERS"

Use FILTER instead of direct column filters.

Please try below updated DAX measures.

Locked Forecast =
VAR SelectedMonth =
    MAX ( dDate[Date] )

VAR LockedMonth =
    EDATE ( SelectedMonth, -4 )

RETURN
CALCULATE (
    SUM ( fForecast[Total Reel Demand] ),
    ALL ( dDate ),
    FILTER (
        fForecast,
        fForecast[Month] = SelectedMonth
&& fForecast[Forecast Key] = LockedMonth
    )
)

Current Forecast =
VAR SelectedMonth =
    MAX ( dDate[Date] )

RETURN
CALCULATE (
    SUM ( fForecast[Total Reel Demand] ),
    ALL ( dDate ),
    FILTER (
        fForecast,
        fForecast[Month] = SelectedMonth
&& fForecast[Forecast Key] = SelectedMonth
    )
)

If you are facing any grand total inconsistencies, Please try below DAX.

Locked Forecast =
SUMX (
    VALUES ( dDate[Date] ),
    VAR SelectedMonth = dDate[Date]
    VAR LockedMonth = EDATE ( SelectedMonth, -4 )
    RETURN
        CALCULATE (
            SUM ( fForecast[Total Reel Demand] ),
            ALL ( dDate ),
            FILTER (
                fForecast,
                fForecast[Month] = SelectedMonth
&& fForecast[Forecast Key] = LockedMonth
            )
        )
)