Expression pedal affecting tone volume knob setting?

[Goldsmith]

Had my first gig with my HD500x recently. Sometimes when I'd press the expression pedal toe switch, my tone's volume would switch to the level the volume knob was currently set to, which was quite annoying. I tested this yesterday and it does keep happening (sometimes, though very rarely, if I just mess with the pedal in general) from time to time. The display briefly shows the amp settings screen as if I had physically nudged the tone volume knob.

 

Is this something that's happened to anyone or should I just take it in to get it repaired?

[cruisinon2]

Any amp parameter can be assigned to the expression pedal...channel volume, drive, anything in the tone stack. Sounds like you may have the channel volume assigned to the pedal inadvertently.

[pianoguyy]

Did you use your pod before taking it to a gig? 

If yes, did it happen at home or at practice, or did this simply start after plugging it in live. 

[Goldsmith]

Any amp parameter can be assigned to the expression pedal...channel volume, drive, anything in the tone stack. Sounds like you may have the channel volume assigned to the pedal inadvertently.

 

Pretty sure I don't. If I would, it would be happening all the time, and I wouldn't be seeing the amp settings on the display.

 

Did you use your pod before taking it to a gig? 

If yes, did it happen at home or at practice, or did this simply start after plugging it in live. 

 

Yes, I was been using it regularly at home and practice for a couple of months. This started after plugging it in live and continued at practice yesterday. I've been stepping away for the past 5 minutes but I can't seem to reproduce it at home.