We have zero information on XPS modules. We've never used them and have no idea what the difficulty you experience may be. You may need to contact XPS to determine what the difficulty may be. If the rest of the transmitter has a difficulty, we can certainly help you with that, but we have no resources to help with non-Futaba equipment.

One thing you may want to check is the integrity of the module pins in the transmitter. If they have been worked in and out a lot, they may have issues on the circuit board.