I am not sure if the OP's situation has anything to do with FQTV/FQTS fields at all. When you book your ticket with APD, they don't allow you to change your FFP number which has been the case since the beginning of time. I have experienced the same with Star redemption tickets on LX as well. Agents couldn't change FFP attached to it even though the ticket was booked for me by somebody else and the FFP belonged to another person. I guess it was largely a system glitch. However NZ would have done that to prevent accruals to another Star programme because NZ uses normal revenue booking classes for redemption.
But I would have thought flashing your eligible physical card would be enough to get you in. After all, not being able to change the FFP number is not your fault.