ddj400 headphone button

have a DDJ400 DJ controller. It is very nervous that the headphones switch works so that I have to turn off the "a" channel first, and after the "b" on. and vice versa. so that you can solve the button to turn off the previous one by pressing the button. This could be solved without further ado in the traktor DJ S2. This seems to be a small thing, but during the party, it would like a lot of unnecessary pressures.