XDJ-RX2 controller link with OBS

Hi there .

I'm using Windows laptop.

When I livestream with just my RX2 I have no problems at all. Problems start when I link another controller to the line in on the RX2. 

The RX2 controls the other controller and the sound comes out of the speakers just as it should but OBS does not pick up the sound from the second controller ! 

Second controller is Pioneer SB2

As soon as I switch and  play a track on the RX2 it picks it up !! 

Any ideas as it's doin my nut in !!

I'm using a virtual audio cable as well so all is as it should be.

Cheers :-)