Convert SUMPRODUCT to SUMIFS

All the xxIF functions require ranges as arguments in certain positions, so you can't perform those INT functions, e.g.,

=SUMIF(INT($A$3:$A1083), INT($A1083), JM$3:JM1083)

... won't work.

I don't use Office365, but am certain that nothing has changed to make that formula not work. I expect you have an errant value in one of those ranges.