Strange blue border around Selected window/link

Strange blue border around Selected window/link - that's really the best I can do for a description

It started yesterday and I admit I may have accidentally hit some keyboard combination that toggles some Preference. It's more than a visual distraction, because it does fade away after

about 10-15 sec, but it disrupts my 'navigation' because tabbing or

using the up/down arrows does not work the way they are supposed to -

and that is NOT acceptable

It affects both Apple and 3rd Party apps: Mail, Calendar, Firefox, Quicken; and more than an hour on the phone with - first a Primary CSR who, about the hour point, transferred me to a Senior rep (I think she called him) who tried a few more things recommended by some chat line he was following

We finally decided I would update the OS from 12.1 to 12.2.1 and I'd call back if the problem persists - well ... and before I call Apple Support again, I'd try here and see if anyone else has seen this. There's an OLD posting about a Black border but this app suggested I start a new Ask