DAX Calculated Column for Comparing Values on Non-Consecutive Dates In the matching context

Hi everyone,

I'm working on a DAX calculation in Power BI where I need to compare a value on a given date with the value on the previous date for the same context of Product, Partner, Projection, and Element. However, the dates are not always consecutive and have duplicates*, so I'm using an Index column based on the date to help with this comparison.

In my example table, I'm encountering an issue where the rows with Index 13 and Index 32 are not recognized as the previous value.

edit*

PreviousValue =
VAR PreviousValue = 
    CALCULATE(
        SUM(FactData[Value]),
        TOPN(
            1,
            FILTER(
                ALLSELECTED('FactData'),
                'FactData[Product] = EARLIER('FactData'[Product]) &&
                'FactData'[Partner] = EARLIER('FactData'[Partner]) &&
                'FactData'[Element] = EARLIER('FactData'[Element]) &&
                'FactData'[Projection] = EARLIER('FactData'[Projection]) &&
                'FactData'[Index] < EARLIER('FactData'[Index])
            ),
            'FactData'[Index],
            DESC
        )
    )
RETURN
PreviousValue

Many thanks in advance for your help!