MEDIANX missing values for dates with no data

Hello all.

I'm looking for some help on this DAX code:

Median Test 3 (next 3 months approved) = 
VAR MedianValueDiscipline =
    CALCULATE (
        MEDIANX (
            SUMMARIZE (
                'Actual & Forecast Project Resources',
                'Actual & Forecast Project Resources'[Work Week Ending Date],
                'Actual & Forecast Project Resources'[Capsule Descriptions.Discipline],
                "Median FTEs",
                    SUMX (
                        'Actual & Forecast Project Resources',
                        'Actual & Forecast Project Resources'[Consolidated FTEs]
                    )
            ),
            [Median FTEs]
        ),
        'Actual & Forecast Project Resources'[Final Consolidated Hours Type] = "Approved",
        DATESINPERIOD (
            'Actual & Forecast Project Resources'[Work Week Ending Date],
            MAX ( 'Date'[EndOfThisWeek] ) - 1,
            3,
            MONTH
        )
    )
RETURN
    MedianValueDiscipline

 

This is producing the following results in a matrix:

Whilst this is giving the correct total value, the rows with null values are incorrect as the Median is only calculating for dates where there is a value. The rows with 'blanks' are from the field 'Actual & Forecast Project Resources'[Capsule Descriptions.Level Category]

 

My question is, how can I force zero values into the 'blanks' and obtain the correct result for each row of the matrix?

 

TIA, Ian