What a mess. Had my order all set up yesterday as a saved/favourite item in the app for when the store went live. Got as far as the checkout, went to pay with Apple Pay, and it decides my billing and delivery address are invalid. Tried editing them, checking the postcode etc, all absolutely spot on.
Eventually gave up and jumped onto the PC and managed to get the order through on there, without changing any of my linked cards details.
Delivery date had already slipped to 28th Oct - 2 Nov by then, pretty disappointed at that.