Gain issues with XDJ RX when switching from line to deck

Hi everyone! 

I’m seeking a solution for a problem I’ve encountered with my XDJ RX. When I play music through the line input from my phone or laptop and then switch back to deck mode with my laptop, the gain knob for the deck stops responding to volume adjustments and is much lower than my other channel that was connected to the laptop from the beginning. I usually fix this by toggling the gain a few times and switching line/deck back and forth a few times but it's not ideal while working a wedding :/any solutions?

Thanks!