DDJ-WeGO4, Master Level Knob No Output

Hello.

I am suddenly unable to control the volume on the DDJ-WeGO4 unit.  I am using a PC Desktop with Windows 10 OS.  I had the mixer for almost for four months already and have no problems with it until now.  The only change that I know of was the recent upgrade of rekordbox to its newest version 5.2.2 but still when I first updated the software it was working fine then suddenly I am unable to control the volume on the Master Level knob. I can control the volume on the mixer sliders and on the volume on the amplifier or speakers.

I have followed your troubleshooting instructions on no master output as seen on previous posts, but to no avail.

Hope you can help me. 

Thanks.