I don't know how, but it looks like a parenthesis was moved.

Your sheet's formula starts as:
=IFERROR((SUMPRODUCT(A$8:A$182>=A2)...

That second parenthesis before SUMPRODUCT should be after it:
=IFERROR(SUMPRODUCT((A$8:A$182>=A2)...

Just copy the equation from the post a few above again and paste it again. There is an extraneous space that this forum put in one of the DATE's. I tried to get rid of it, but it keeps appearing.

Probably just better to move the parenthesis.