Issue with SUMX and Row Duplicates

Hi, any help on this please?

I slightly changed the data and calculations and also tried a variation of the code with lookupvalue.

Original measure:

LabourCost1.1 = 
VAR _Result =
    SUMX (
        Hours1,
        [Hours1]
            *
            VAR _HourlyRate =
                MAXX (
                    FILTER (
                        HourlyRates,
                        HourlyRates[DEPARTMENTID] = Hours1[DEPARTMENTID]
                            && HourlyRates[YEAR] = YEAR ( Hours1[DATEENTRY] )
                    ),
                    HourlyRates[HOURLYRATE]
                )
            VAR _HourlyRateNoValuePast =
                MAXX (
                    FILTER (
                        HourlyRates,
                        HourlyRates[DEPARTMENTID] = Hours1[DEPARTMENTID]
                            && HourlyRates[YEAR] = MIN ( HourlyRates[YEAR] )
                    ),
                    HourlyRates[HOURLYRATE]
                )
            VAR _HourlyRateNoValueFuture =
                MAXX (
                    FILTER (
                        HourlyRates,
                        HourlyRates[DEPARTMENTID] = Hours1[DEPARTMENTID]
                            && HourlyRates[YEAR] = MAX ( HourlyRates[YEAR] )
                    ),
                    HourlyRates[HOURLYRATE]
                )
            RETURN
                IF (
                    NOT ( ISBLANK ( _HourlyRate ) ),
                    _HourlyRate,
                    SWITCH (
                        TRUE,
                        YEAR ( Hours1[DATEENTRY] ) < MIN ( HourlyRates[YEAR] ), _HourlyRateNoValuePast,
                        YEAR ( Hours1[DATEENTRY] ) < MIN ( HourlyRates[YEAR] ), _HourlyRateNoValueFuture
                    )
                )
    )
RETURN
    _Result

Variation with lookupvalue:

LabourCost1.2 = 
VAR _Result =
    SUMX (
        Hours1,
        [Hours1]
            *
        VAR _HourlyRate =
            LOOKUPVALUE ( 
                HourlyRates[HOURLYRATE],
                HourlyRates[DEPARTMENTID],Hours1[DEPARTMENTID],
                HourlyRates[YEAR], YEAR ( Hours1[DATEENTRY] )
            )
            VAR _HourlyRateNoValuePast =
            LOOKUPVALUE ( 
                HourlyRates[HOURLYRATE],
                HourlyRates[DEPARTMENTID],Hours1[DEPARTMENTID],
                HourlyRates[YEAR], MIN ( HourlyRates[YEAR] )
            )
            VAR _HourlyRateNoValueFuture =
            LOOKUPVALUE ( 
                HourlyRates[HOURLYRATE],
                HourlyRates[DEPARTMENTID],Hours1[DEPARTMENTID],
                HourlyRates[YEAR], MAX ( HourlyRates[YEAR] )
            )
            RETURN
                IF (
                    NOT ( ISBLANK ( _HourlyRate ) ),
                    _HourlyRate,
                    SWITCH (
                        TRUE,
                        YEAR ( Hours1[DATEENTRY] ) < MIN ( HourlyRates[YEAR] ), _HourlyRateNoValuePast,
                        YEAR ( Hours1[DATEENTRY] ) < MIN ( HourlyRates[YEAR] ), _HourlyRateNoValueFuture
                    )
                )
    )
RETURN
    _Result

I tested these 2 measures on 3 different Hours Tables with 2 rows only. Only the Hours3 Table contains duplicate rows.

HOURLYRATES Table

HOURS1 Table

HOURS2 Table

HOURS3 Table

For each of these 3 Hours Tables I tested both measure variations, returning the following result.

The total duration in all Hours Tables i 16 hours and the Hourly rate to be considered is 25€/h. Consequently the correct result for labour cost is 400€, which is correct for the tables (Hours 1 and Hours 2 ) with no duplicate rows. The measures for Table Hours 3, containing duplicate rows, return 800€ as a result, which is incorrect.

The attached the PBix sample file under the link below:

https://we.tl/t-CnlYp5QlIQ

Best regards