NO MIDI mapping possible with Serato DJ Pro / Soundswitch

You bet there is...

Hi, 

I know that Serato provides MIDI settings when connecting an external device such as a Pioneer DDJ SR, SX, Denon MCX 8000, Roiland DJ505, Numark NVII. 
With all these external controllers I succeed to MAP the channel faders in the software (both Serato DJ pro as you dexcribed as Soundswitch and my lightshow works perfectly on the 2 deck faders). 

The issue I have is with my latest controller the XZ. He recognizes (in Serato AND Sounndswitch the controller). Nothing wrong so far. 
But when I try to MAP those 2 channel faders - there is no mapping possible; he doesn't react when I give the order to do. 

I replaced the USB cables, installed MIDI monitor studio (he finds the XZ), I tried different USB-C ports on the macbook pro, updated everything, checked my MIDI configuration, but no mapping possible (no reaction) 

Kind regards, 
Nick

As the XZ has two different MIDI devices, are you sure you've selected the correct device, and is the mixer in MIDI mode?

I have had the exact same issue.   I have the "Allow Serato Hardware Remapping" checked on both sections and cannot midi map the XDJ mixers faders to Serato or Soundswitch.   Other buttons like hot cues or even the pitch fader midi map no problem but the volume faders give out zero midi input.