DDJ-FLX4 Headphone issue

Hi,

I think there might be a problem with the hardware but am not sure. So, i am 100 percent sure that my audio settings are correct (rekordbox), but i can always here the music from the master track in to my headphones, even if all the cue buttons are off, or even if the headphone knob is all the way to the cue side. Normally I should not here a thing threw my headphones without any cue activated and I should here only the channel in cue when the headphone knob is all the way to cue side, am i right? If I am can anyone help or have an idea whats going on? (DDJ-FLX4)

Thank you