I have the same issue with the second MiniLab MK2 already.
The controller is connected to an iPad Pro (V1) via USB and in all Apps the knobs (#2 is the worst) are jumpy.
In a MIDI Monitor I've seen that in a Slow sweep up the value are "hanging" (nothing for 0.5 sec, then 3-6 value at once) and jumping back (up to 6 units, all separate values).
I sent the controller back.
Is this a general problem?