That is REALLY strange!
All the preamp presets use a pedal to control level. By default though we patched the pedal to assign 1 set to high. This enables a full level setting which doesn't require any pedal to really operate these presets. The pedal is only usable if the user changes assign 1 from high to pedal 1 or 2, depending where the pedal is connected to.
I'm not sure if there is any hardware issue in this unit.
Let me check our engineering.