caj821

I finally figured it out.  I went to settings/accessibility/touch/call audio routing.  I had set it to speaker.  When I reset it to automatic, all was well.

I'm surprised that the guy who took my call at Apple support didn't at least ask me to check that out.  Instead, he said it must be the car.  Well, my wife's phone worked fine with the car.  Comparing how our phones acted led to the fix.