OK, after fighting this for days, I finally grabbed a ferrite and wrapped my USB cable (never had an issue with this cable with previous setups) just in case this was an RFI issue:

https://wsjtx.groups.io/g/main/topic/69952737

Absolutely no effect whatsoever.  Continual sound input error dialogs. The Microphone privacy switch is not an issue as I posted earlier.

So, I set up an elderly Toshiba Satellite running Windows 7, hooked it up with the same cable same driver, same software, same place in the shack, and it's been running for 7 hours w/o a hitch.

The computer is a brand-new Asus VivoBook 17 K712EA, and I never dreamed that I would have any issues with it. I've got a limited amount of time to return it.  I'd really appreciate feedback.

73
Jeff Elkins