CDJ 900 nexus + XDJ 100mk2 + DJM 800 issues

I am struggling to get the CDJ and XDJ to play their sound through the DJM 800 mixer. I am able to connect them seperately to Rekordbox so that the play seperately but dont seem to want to play thier audio thorugh the mixer and only through the computer which means I cant mix them. Any ideas on how to get them to channel through the mixer? Rekordbox is currently in performance mode.