On some presets, in the volume setting, my expression pedal is at zero in the heel position and at 100 in the toe slot. And it sounds this way. But in other presets, even though it looks like it's at 0/100 in the heel/toe settings, it sounds like it's at 20% in the heal, dips and gets louder. I've read about using TS vs TRS cables, but I have a Mission EP1-L6 and this just takes a regular instrument cable. Plus it seems to work fine in some settings. Why are there inconsistencies between presets, and how can I sort this out? I can add screenshots if necessary.