Strange Error

[FaeFen]

Does anyone have any idea why this code only searches the first row with a matching header instead of every row with a matching header?

=COUNTIF(INDEX($A$4:$F$360,MATCH(LEFT(L$4,3),LEFT($A$4:$A$360,3),0),0),$J16&", "&LEFT($K16,1))+N16

Array $A$4:$F$360 with header $A$4:$A$360,3 trying to search rows that share the beginning of L4 for [Last Name], [First Letter]

I could have sworn I have used this before.

 

[Fluff]

Hi & welcome to MrExcel.
Match will only ever find the first match. How about

=SUMPRODUCT((LEFT($A$4:$A$360,3)=LEFT(L$4,3))*($A$4:$F$360=$J16&", "&LEFT($K16)))+N16