And, at least for the moment, the issue has disappeared after a restart. I'll never know what was up, but I'll keep an eye out for the issue to recur, and I hope it won't.
These sorts of bizarre and inexplicable things do happen, and very often a power cycling will fix 'em.
Brian - Windows 10 Pro, 64-Bit, Version 2004, Build 19041
It’s hard waking up and realizing it’s not always black and white.
~ Kelley Boorn