Add my wife as another user with a brand new Dell with Windows 11 Home pre-installed - which I upgraded to Pro to see if it fixes the problem - that exhibits all the various behaviors in this thread. It seems to focus on MS Office once it begins failing because I can still copy/paste in apps like Notepad.
My wife wants to return the computer and get another computer (or get another husband) thinking it will solve the problem. From the history of this issue, it may not be worth the effort to swap it out and risk the same result.