MS20 IC notched knobs

Hello everybody I have a problem with a midi controller Korg MS20 IC.
I use or with Korg Ms20 plugin legacy or V2.0.
The problem is that the four notched knobs (waves and pitch) don.t work.
Try changing USB câble. Try standalone plugin (no Daw). Try everything.
Think it is a hardware problem? Any idea ?verty thanks for help I looove this contrôler.