SUM IF not working as expected

=SUM(SUMIF(F:F,{">0","<"},H1247:H1250))

My understanding is the above formula is looking for a number in column F. If that number is greater than or less than zero, it will then sum the relevant cells in between H1247 and H1250.

The range is small as I test it.

The interesting issue is all 4 relevant cells H are double digit positive numbers, but the result is returning as a negative.

Any insight as to what I'm screwing up? The data in column F is set to "number" not text, first thing I checked.

Thanks.

Brett