I got it figured out…
After creating the widget upon Begin Play in my Level BP, I needed to SET the “Game Messages” variable at the end of that sequence (as shown below).
My mistake was that I’d simply created a variable in my Level BP of type “Game Messages” and tried to do calls off of THAT (which didn’t work.)
All is well now…BIG THANKS TO ALL WHO HAVE CONTRIBUTED TO HELP SOLVE THIS. You have my gratitude.