Me and my boyfriend are both using the curve card for the past two weeks. In the initial testing of the cards we added one of my cards to his curve account. Now even after he deleted the card it is no longer possible for me to add my card to my account. I understand that a card cannot connect to both our accounts but now that he deleted it why I still have a problem adding it.
This is a known issue:
Hey @dionstro, welcome to the community!
This is a known issue, the official response is as follows: