Knob 1 set to mixer/volume - always pops when first moved

[jetrocker]

I have timber 2 volume mapped to knob 1 in a combi. Every time I go to that combi and try to move the knob at all for timber 2 volume, I get a distinct pop sound first...unless I move the knob up and then down before I play. I've tried both settings, catch and jump, and neither makes a difference. Is this an inherent hardware operation that can't be eliminated? If so, is there any other means to control the volume of this timber that won't allow this to happen?

I tried an expression pedal, but if I set that up globally, it effects every patch I have. Maybe I'm missing something? Thx, Mark