Hi, I'm having the same issue.
My Keylab 88 mkii triggers random fader information too when pressing B3, A#3 and A3, and these three keys are, suspiciously, the only ones that make a clicking sound. When pressed they have a distinctively different sound from the rest. I bought my Keylab a year ago and have always noticed the clicking of the keys but had not payed much attention to it, and I've only now realised that this might be related to some mechanical problem by which these particular keys trigger a signal that they shouldn't. Have you had any more information about this?
Judging by the striking coincidence of our problems, as it seems this arises specifically in the same region of the keybed, I fear this could be a hardware problem that some units have right out of the factory. My theory might be wrong, but to me the similarities between what we are both experiencing point towards this.
I will try to contact Arturia directly, though I haven't got any experience with their customer support and I don't know if it's easy or not to get information from them directly. I would very much like to hear if you have gotten any more info, or to find somebody else with this same problem.