Tethered Shooting in Lightroom Classic 9.1 not working on Canon 5D Mk III.

[Radiant_finder16B6]

I just upgraded my OS from 10.14 to OS 10.15.2, and upgraded from the 2019 version of Lightroom Classic to the new LR Classic 9.1.  I have a Canon EOS 5d Mk II and 5d Mk III.  Both worked well with Tethered Catpure until these OS and LR upgrades, and now when I start Tethered Capture, it doesn't recognize the camera.  I checked connections, restarted and reconnected the camera, restarted the computer, deleted Lighroom Preferences, updated my camera firmware.  I tested my cameras on an old computer with OS 10.10 and Lighroom 6, and Tethered Capture still works great on that system.  

When my camera is connected, I am able to use the Lightroom Import window to navigate to the card in the camera and download images into lightroom.

Another puzzle piece, is I installed the October 2019 upgrade to EOS Utility, and it also is unable to recognize my cameras.  But Lightroom shouldn't require EOS Utility to operate the 5d Mk III, right?

I was on chat with Adobe tech support for 1-1/2 hours, and they weren't able to solve the problem. They suggested I contact Canon support for help.

Can anyone explain how I get Tethered Shooting to work?  Thank you!

[gingerman]

MacOSBigSur 11.6.5    (  2.6 GHz Quad-Core Intel Core i7 )
Canon 5D ii 
Cannot Connect to camera via USB
USB item not detectected in About Thi Mac >> System Report >> USB
Camera not appearing in finder or Lightroom. 
Forget Eos Utility.