INDEX Match

I’ve been at this for ages, answers probably staing me in the face, but I just cant work this out!

L26 returns incorrect information. Input parameters are F29 and F30. In its current state, it returns the value “b”, where I think it should be returning “1”, i.e the intersection point for “3Ph” & “Single-core 70°C thermoplastic non-arm Cu Table 4D1”

What am I doing wrong?

Many thanks.