For many years, we have flipped at least one Chase/UA card to get the 60/70k bonus. We usually keep an Explorer, Quest, or Club card. One in my name, one in my bride’s name. We’d keep one for two years, get approved for a new one, then cancel the old one.
This year, however, I applied for a new Explorer card. I hold a current Quest. I was rejected saying that I already hold this card. The only Explorer is in my wife’s name, though I have signature rights on it.
Credit rating is currently 819 so that’s not the issue. Spend on the Quest is close to $50k. Spend on the Explorer is, maybe. $20k.

What’s going on? Do I have to cancel my wife’s Explorer before applying for another one?
or should I apply for a Quest for her?

Thanks!