Later today we came back to sleuth the problem and decided to check the Bandlab Assistant web link that goes to https://www.bandlab.com/feed and found a notification that informed us that we had to confirm our email address. We are a new account to Bandlab!
After we had verified our email address, Cakewalk was able to activate (we did launch Bandlab Assistant as the Administrator user, so not sure if that's also part of the puzzle). After activation, we just launch Bandlab Assistant, then launch Cakewalk - as a normal user - and all is OK now, Cakewalk can save stuff!
If this email confirmation was indeed the final puzzle piece, then I think this important bit of information should be an emboldened part of the FAQ.