MC3000 issue with pitch (tempo fader)

I’ve recently purchased this Denon DJ MC3000 from someone (2nd hand). And I have now noticed a weird behaviour on the left pitch (tempo fader). Basically, it looks like it’s a bad contact or something similar, when on the neutral position on the controller (the MC3000) it moves on the software (Traktor or VirtualDJ).

I thought maybe it’s the software I used, so I tried with both Traktor & VirtualDJ. Same issue.

See the video below showing the issue, you can also see that it works fine on the right pitch, the issue is only on the left pitch:

Am I missing something or am I right to believe the hardware (the MC3000) has a defect?

if it shows same problem in two softwares then it’s a confirmed hardware problem. try googling how to clean faders, if it doesn’t help then new one is neccessary.