Hi, I'm having the same issue. I've contacted Apple support and they said nothing was wrong with my billing or payment information (because I'm using apple giftcards and not a credit card). I've tried all the things they've suggested, but none of them worked. So then they told me to contact the app developer, so I used the customer service option in the game, but they told me that this issue is an Apple thing so I should contact Apple. I've tried logging out and logging back into both my Genshin account and my Apple account. I've restarted my phone and the game. None of those methods worked. Lastly, I've tried using my iPad, but that doesn't work either. What do I do?