Logitech headset not working after Audio driver update

Latitude 5420 and Logitech H340 have been working happily together since purchase.  Last week the Dell Update app installed a new BIOS firmware (1.8.0) and Realtek Audio Driver (6.0.9163.1).  After that, my laptop would crash when trying to do anything with sound/mic - eg start a Zoom meeting. 

Its very annoying and even installing previous version of Audio Driver ( 6.0.9126.1) didn't solve it.  Now, with only a mouse and the headset plugged in, I get no sound from the headset, even the ping from using the volume slider.

Troubleshooting with win10 doesn't help.

Anyone else have this?