Sorry for boomer tier question but my card didn't come with a sticker, the online activation wants me to create a new account (I'm an existing customer - this is a product change), and there's no number to call to activate. WTF Amex?

I recently got a new iPhone. The first time I tried logging back in to the Amex app it asked me to confirm my card. Though I have already had and used this card for almost six months, I filled out the details, verified it was me with a one time code sent to my phone, and it said I was good to go. It took me back to the login screen and then put me through the same process. I did this four or five times, deleted the app, and restarted my phone before contacting support. I have spoke with two separate agents over a two week period now, and both have told me they have no reason why that is happening, it shouldn't be happening, and their "tech" team is saying the same thing. That I just have to wait. I figured a few days, maybe a week would do the trick. It's been two weeks with still no capability of logging in to the mobile app. Has anyone else been experienced this?