Apple Pay not working due to risk rating

I got a new iPhone 16 Pro in February. Transferred everything across from my old iPhone 12 mini. All of my bank cards worked fine in Wallet, on my old phone.

Tried to add all my cards to the new device. My two UK-based bank cards (Mastercard) worked the first go. My other cards - with two Australian-based banks (Visa and Mastercard), my Amex, and my Wise, all declined with the same error message which said "Card Not Added" and to contact the card issuer.

I called Apple support that afternoon, they ran a bunch of diagnostics, said it all looked normal, and told me to wait 7 days before calling back. Amex called me the next day saying they'd detected fraud and to check whether it was me trying to add the card. I said it was, they stayed on the line with me and let me add it. So - I have 3 cards that do work in Apple Pay: 2 from Monzo in the UK that uses Mastercard as the PNO (worked automatically when I tried to add it), and my Australian-based Amex (needed Amex to call and sort out).

It is also possible for me to add my Australian Visa that keeps declining on my device, to my boyfriend's iPhone - works every time (I've done it at least twice). This suggests it isn't to do with the card, bank, or PNO.

I've called my other two banks and Apple countless times over the past four months. No one can resolve this. I've read other posts in this community about risk ratings and profiles and I'm certain that this is what has happened with my account. One of the banks contacted Mastercard for me who said that these risk ratings are out of their control, too.

Apple refuse to accept that it's anything to do with them. My next step was going to be to create a new Apple ID and sign in on either my current or old phone, and add the cards, to prove it's something to do with the Apple ID (noting that after I removed the cards from my iPhone 12 mini, I couldn't re-add them - started getting the same error message as on my 16 Pro).

The part of this whole story that I don't understand is why some of my cards work when others don't - the Monzo cards are Mastercard, so is one of my Australian bank cards, but one works and the other doesn't. Amex had the same problem as other cards but actively called me to run a security check and were clearly able to lift it to let me add the card.

I've tried contacting Visa and Mastercard directly but they won't deal with individuals. Apple have sent me up the wall with their total lack of help. One of my banks doesn't even *see* my requests to add my card in their system - it's clearly getting blocked before it even gets there.

I've seen questions from people with the same problem - did anyone ever manage to get it fixed? If you did, how did you do it? And if there's anyone with intimate knowledge of these processes and can explain to me why some cards work but others don't with the same Apple ID (despite, presumably, the same risk profile or rating), I'd love to understand.

This whole episode has turned me so hard off Apple, I regret buying this new phone so much. If it doesn't get resolved I think I'll just resell and move to Android...

Appreciate any and all advice that people can provide. Thanks so much!