sumproduct formula returning wrong value or 0

[Dokat]

Hi,

I have below formula that returns column number in a table however in some cases based on the slicer selection it returns 0 or wrong value. Did anyone come across similar issue and have a solution for it?

=SUMPRODUCT(('Source Data'!$B$7:$BF$59=LOOKUP(2<wbr>,1/(1-ISBL<wbr>ANK('Sourc<wbr>e Data'!F:F)),'Source Data'!F:F))*(COLUMN('Sourc<wbr>e Data'!$B$7:$BF$59)))


Thanks