Thanks Mac Jim ID! A few comments to some of your questions and statements, as I understand verification of an account especially upon setting up, but the timing and nature are so seemingly random:
I had previously registered my Apple Cash account when I set up Apple Pay a few years ago, but do understand it may be requested to be verified but for what reason?
The transactions that I cannot complete are for typically <$10, when my kids are asking for money for a snack or to go to lunch. I rarely use it, typically those requests go to my husband.
My husband and I have individual Apple accounts but we are tied together in a family account (not sure if I stated that properly).
I did get a prompt that I would need to verify my account, but it happened randomly one day in response to my kid's Apple Pay request of maybe $8. Once I got to the window that requested the full SSN, I canceled out as I was uncertain why this was being requested and was concerned about the integrity of the prompt.