Can you "find" them using HVACPro direct connected to the N2 bus ?
Double check your N2-bus wiring.
If so, I think there was a patch/upgrade available that may help (Rev 1.1 ?) If I remember right that FX is a rev 1.0. I will check and post more later.
If sense were so common everyone would have it !
Any advice provided is worth exactly what you paid for it, not a penny more not, a penny less !!