Woohoo! I got it!!
:
IMPORTANT: If you have an ATI graphics card, AMD Pro software stops you from being able to use CONTROL+SHIFT+[KEY] combos. I disabled the hotkey assignments in AMD Pro software, and now I'm in business!
I suspect Jeff Groves and vickers either have Nvidia graphics cards, or do not use AMD Pro for ATI cards - that's why it was working for them.
The brief period on 11/23/2024 when it worked for me? Coincided with when AMD Pro happened to crash. It all makes sense.
If skwasjer ever comes back we should tell him.