DDJ-400 headphones mixing knob disconnects my controller after I try to pull it all way to cue

Hey, I recently bought ddj 400 controller and I have some problems with it. Firstly, I had some issues with headphones cue. I couldn’t hear any sound in my headphones when I pressed cue buttons(master cue button is always on), but I kinda managed it out by changing headphones output to master. However my headphones mixing knob is not working and when I try to pull it all down to cue the whole controller just disconnects from my computer. When I pull it back a little, it turns back on. It’s really weird and I hope this problem is not related to controller it self, I don’t want to change it( Please help me.