I am Using the SumProduct function to sum the visible contents of a datatable that gets data from access. this function

=SUMPRODUCT(--(SUBTOTAL(3,OFFSET(INDEX($H$12:$H$50098,1,1),ROW($ H$12:$H$50098)-ROW(INDEX($H$12:$H$50098,1,1)),0))=1),--($I$12:$I$50098="1310"), $H$12:$H$50098)

works

but

=SUMPRODUCT(--(SUBTOTAL(3,OFFSET(INDEX($H$12:$H$50098,1,1),ROW($ H$12:$H$50098)-ROW(INDEX($H$12:$H$50098,1,1)),0))=1),--($I$12:$I$50098=A6), $H$12:$H$50098)

does not. Even though A6 = 1310.

Can anyone explain why this may occur?