Have you gone through the USB settings for the rig and checked them against some set that is known to work? It sounds like the audio signal that is generated by the receiver is not getting to wsjt-x. That could be a problem in the rig, in the USB cable or in the USB audio drivers or the windows 10 audio settings. I think you need to verify that your rig is set up for all audio signals to and from the pc are set for the USB audio codec and that wsjt-x audio settings are too. Also, your windows10 audio settings have to be verified including checking to make sure the USB Audio CODEC drivers are installed correctly. Maybe the gods of bits and electrons have conspired against hams today and you are fighting the battle to save us all.