Shift-touching a fader to set level to 0 dB is not consistent in the Artist/MC Mix.
If you shift-touch the fader really fast (your touch is very quick and light), it works.
If your touch MOVES the fader when shift-touching it, even slightly, or the touch lasts longer than a fraction of a second, it doesn't work. In this case, the DAW (in my case Logic) still registers it as shift-touch and the fader in the UI moves to 0db. The physical control surface fader does not move.
A good video presentation of the problem: