As a closing anecdote, this is the second time I've used these forums to try to solve an annoying MS problem. The first one, with a bogus message when starting up MS Office, was never officially fixed by MS, or at least they never claimed they did. After 5 months of multiple Win10 and MS Office software updates, the problem just quietly went away. It was really annoying that there was no announced solution to it, only stuff like what has been posted in this thread.
What worries me about this Conexant problem is that the above problem was with Win10 running MS Office 2019 or 365, products actively supported by MS. The Conexant driver, now apparently owned by Synaptics, could have fallen into digital no mans land. There may never be a supported solution for an old driver. I can only hope that Synaptics will do the right thing for the next Windows version for the driver they own, otherwise we'll all be talking again :-)
Good luck to all.