Thank you, Brizbee. I've tried Safari, Firefox and Chrome. I don't have Edge, but I'll look into it.
So, I've downloaded and tried Opera and Vivaldi - still no dice. And, I work in Mac OS so Edge is not a likely option (I hardly ever use Parallels or anything like that - haven't updated those in years).
OK, I finally got it! I've been trying to make this work on my Mac Pro with various browsers to no avail. Then I thought, let's try the iPad - and it worked like a charm.