I will try to help since I have run into problems with my dh too. I was on the phone for way too long ¨just to get a blue card¨ that used to be sent to us without a problem! I am old too, in many ways life was easier before computers! And now a MDE has to be set up for him along with Apple Pay.
First, the Y lets a cm know that you are entitled to the discounts, the ND would mean you have a white card.
You can not have his affiliation show on your account unless he has a dvc account. It was a real pain for us since I had made an account many years ago, forgot about it when I got my own laptop and then made a new one, which meant he couldn´t make his own account until they were able to delete that old account. Now I have two accounts to manage since he doesn´t want anything to do with this.
What a pain!