When I use the following SUMIF statement, it does not SUM the values in the 2nd and 3rd columns of the range.

=SUMIF($B$1:$B$10,C20,$L$1:$N$10)

It only sums the values in L1:L10, but does not include M1:M10 or N1:N10.

If I change the range so that it is in the same column; L, M or N, then I get the correct amounts for that column. But it doesn't seem to work if I create a range spanning more than one column.

Am I doing something wrong? Thanks.