STAB not working in HC12 Assembly

Question

so I've come up with the following code thats calculating the required byte / word offset of an array.

    org $1000
NROWS db 3
NCOLS db 3
D2ARR_1 db 0, 0, 0, 0, 0, 0, 0, 0, 0
D2ARR_2 dw 0, 0, 0, 0, 0, 0, 0, 0, 0
byteOffset rmb 1
wordOffset rmb 1
row db 2
column db 2

    org $4000
Main:
    ldaa row
    ldab column
    MUL
    stab byteOffset

    ldaa row
    ldab column
    MUL
    ldaa #2
    MUL
    stab wordOffset

But for some reason the store accumulator b isn't working, I'm debugging in a simulator and the memory location of byteOffset and wordOffset never change. They've been defined using reserve memory byte, as oppose to reserve storage, which I believe is correct (I've tried both) But can't seem to figure out what the problem is as to why it's not storing. The value is correct in b but the stab line is simply doing nothing.

In my debug the command being executed is

4007  STAB  $101d

with accumulator B containing the value 4 and memory location 101d being completely free and writable.

Any help would be appreciated,

Thanks