I have this formula which is not giving the expected results

=SUMPRODUCT(LEFT(K5:K1002,1)="8",(A5:A1002)=TRUE,( Y5:Y1002))

The result I am getting is 0. What I am trying to achieve is to sum the
numbers in Y5:Y1002, if the corresponding cell in K5:K1002 begins with
an "8" (account # entered as text, example, 800-000-900) and the
corresponding cell in A5:A1002 is not blank. TIA

Greg