Excel formula works when broken in two parts, but not when added together

I have an excel formula:

=SUM(SUMIF(INDIRECT("'" & $E$42 & "'!C17:C190"),{"Nord*","Grav*","Arachas*"},INDIRECT("'" & $E$42 & "'!$AH$17:$AH$190")))

that works fine. I want to add to the above with this which again, works fine on its own. The result of the above is 986,000 and the below is -186,000

=SUM(SUMIF(INDIRECT("'" & $E$42 & "'!C193:C250"),{"Nord*","Grav*","Arachas*"},INDIRECT("'" & $E$42 & "'!$D$193:$D$250")))

The sum product of each formula is correct and I simply want the result of one plus the other,so I would expect the answer to be 800,000 (ie 986k - 186k) but when I add the formulas together like this:

=SUM(SUMIF(INDIRECT("'" & $E$42 & "'!C17:C190"),{"Nord*","Grav*","Arachas*"},INDIRECT("'" & $E$42 & "'!$AH$17:$AH$190"))+SUM(SUMIF(INDIRECT("'" & $E$42 & "'!C193:C250"),{"Nord*","Grav*","Arachas*"},INDIRECT("'" & $E$42 & "'!$D$193:$D$250"))))

I get a different answer (428,000)....anyone know why?