DDJ SR2 - Headphone and output out of synch

I have just opened my DDJ-SR2 and the output from the speakers and the headphones is completely out of synch rendering it impossible to cue in a song. I have turned the latency down on the Serato controller to the minimum (running via a MacBook). I am playing the sound through speakers attached to the Master 1&2  Out and via a Sonos Amp.

Any suggestions on how and why this is happening and how to fix it ?