Apple Pay default shipping address

I moved home last year, and I'm having massive issues with Apple Pay ever since. In short, my default shipping address insists on being my old address

• I've validated my address is correct in my contact card
• I've validated that my shipping address is the correct one for all my cards in my Apple wallet, thought settings > Wallet & Apple pay, and validated that my current address is the default shipping address
• I've validated my address is correct in the iTunes Store (via the account section of Apple Music app on Mac)

Actually, I removed all traces of the old address, so its not even an option to set the old address in settings > Wallet & Apple pay any more.

Yet, every single purchase on websites, using Apple Pay, defaults to my old address..