I have an iserror formula i.e.,

if(iserror(a1),0,a1)

that is showing a non-zero value, one which I completely believe is correct.
However, when I go to the cell, hit F2, then F9, it shows #NAME?.

I also tried F2, then ctrl alt F9, but still got the same #NAME? result.

Why does this happen?

Thanks,
Dean