The problem could be a bad FBV Express (internally) or more likely, a kinked or broken wire in the CAT-5/Ethernet cable that's connecting the pedal to your amp.

The first thing I'd try is a new ethernet cable, or at least a different one. Most households have one these days, if not you can find them at Best Buy or a computer store for relatively cheap. Also, double-check the pins on both the amp and the FBV Express. If there's a slightly bent data pin on either of the two jacks, that could be it. Corrosion on the pins could also prevent data from being fully passed from one device to the other.