CC121 fader moving erratically and hitting limits -- out of control

Hello,

I am experiencing a serious issue with my Steinberg CC121. The motorized fader behaves erratically: it starts moving up and down very quickly until it hits the physical limits of the fader track.

I have already tried adjusting the sensitivity options in Cubase, but the behavior remains the same. When selecting a track in Cubase, sometimes the fader jumps all the way up, sometimes all the way down, and sometimes it just moves rapidly back and forth as if it has gone out of control.

The power supply is properly connected. I have also replaced the USB cable to rule out connection issues, but the problem persists.

Could you please advise on how to fix this, or let me know if the unit requires servicing?

Thank you in advance for your support.