1/ Switch on CC121
2/ start Cubase 8 Pro
3/ Activate a Cue send from Mix console
4/ open control room and activate the metronome for the cue send
5/ Put the mouse cursor on the metronome volume or pan and using the Ai knob of the CC121, try to increase/decrease the metronome volume or pan => the Ai knob has no effect on the values.
6/ Now, use the mouse wheel to increase/decrease the metronome volume or pan => it’s working
Do you reproduce this behaviour ?