Volume status while changing performances

Hi,
if I switch to another performance in performance mode with my boss fs-6 footswitch while having my volume pedal (yamaha expression pedal) down to zero, it always defaults back to 100% volume. Can I change this?

Thanks.
Andre.

No I have not locked it in the rig menu, but set as wahwah in the system settings, that defaults to a volume if no wah effect is active. If I set it to a volume pedal the performance switch keeps the volume position. Fine.

But sadly so I lose the wah function. Mhhhhmmm.