Official comment
Hey Adrian,
The XDJ-RX2 is sending the fader position data to rekordbox, allowing it to keep the control as you indicate, but the DJM-900NXS2 works as an external mixer and thus relies on the on-air status to manipulate the deck selection for lighting. Your best bet would be to change the lighting preference to MANUAL instead of AUTO, then map a keyboard shortcut or other control to change the lighting selection.
