DDJ RB - Crossfader only working on one side properly

My crossfader is only working on left deck. When playing left deck and move crossfader to right, left deck can still be heard. When playing right deck, and move crossfader to left, sound cuts out (left deck is not playing). When both decks are playing, crossfader when moved to left, only left deck can be heard. When crossfader moved to the right, both decks are heard(mixed sound). Please help. Ryan