Sumifs & sumproduct not calculating correctly in worksheet

Hi everyone. Would appreciate any help for this since I'm completely brain dead viewing sites and trying to figure out where I've gone wrong....

Book has four tabs, but the two I am using for the formula which has me stumped are:
Detail tab (consisting of columns A through J) and 5,234 lines (ack!)
First row is the column description:
A1: Sales #
B1: Sales Date
C1: Salesperson Name
D1: Salesperson ID#
E1: Sales Code
F1: Item Description 1
G1: Item Description 2
H1: Qty Sold
I1: Per pc price
J1: Extended Cost

Sales code Tab (consisting of columns A through O) and only 23 lines
First row is the column description
A1: Sales Codes
B1: Description of Code
C1: Jan-15
D1: Feb-15
E1, F1, G1, H1, I1, J1, K1, L1, M1, N1: subsequent months (ie: MAR-15; APR-15, etc.)
O1: Yr end total

What I am trying to do in the Sales Code sheet is calculate how much was made in sales each month by Sales Code (based on the information in the “Detail” sheet) - and it isnt working. I tried the sumifs:

=sumifs(detail!J2:J5234, detail!e2:e5234,A2, detail!B2:B5234,C1)
But this didnt grab all the extended sales for all the sales categories.

So then I tried SumProduct:
=SUMPRODUCT(--(Detail!E2:E5234=A16),--(Detail!B2:B5234=D1),--(Detail!J2:J5234))
And this looked like it worked - but again, it didnt grab all the extended sales for all the sales categories.

I tried doing a pivot table, but since the information needs to remain static to feed data to a chart, it wouldnt work. I've also tried creating an array, but for whatever reason, the Ctrl-Shift-Enter will not work, so I tried the SUMPRODUCT. Which still doesnt grab all the info. I even copied and pasted (special) the information from the Detail sheet in case there was a hidden formula or wonky setting.

I've no idea what I am doing wrong, and its frustrating because whatever the fix is, I will need to apply it to an additional sheet in the workbook, but instead of sorting by Sales Code and Month, it will sort by Salesperson and Month - and there are 197 rows of salespeople in that sheet. I've been trying to work it out on my own and have finally conceded defeat. Maybe I am just standing too close to the problem and fresh eyes will help?