Values differ in Source then PowerBI from

[Yrstruly2021]

I woud like to know, why my values differ in PowerBI. I got  value in the source of -1167071.32 and in PowerBI -1887965.0199999851.

Change in Capex Creditors = 
CALCULATE (
    -SUMX(
        FILTER(
            'ZTBR',
            'ZTBR'[Roll_Up_Function] IN {"Change in capex creditors"}
        ),
        'ZTBR'[Amount in USD]
    )
)

[Greg_Deckler]

@Yrstruly2021 Well, first, no need for the CALCULATE. Second, what is the source and what is the formula you are using in the source?

[Yrstruly2021]

The source is Postgres. I am converting money values from ZAR to USD. I tested the conversion data in DB and its correct Why am i getting such a big difference in values