I'd like to SUM certain cells if they match specific conditions.

In my specific case, the condition is that if the cell in column D (Solved) returns false, sum the column E (Subtotal)

The function I wrote is:

=IF(([Patients(D2)]=0), SUM([Patients(E2)]), 0)

It works only partially. Indeed, as you can see from the second screenshot below, it "sums" ONLY the last row.

I've been working on this function for some days, and this is the best I can do now.

In this case, the "TOT. to pay" should be the same amount as "TOT." cause the company didn't solve any of the fees (column solved).