Apple Pay for movie purchases not going through

Here's a weird one. So im trying to buy some movies from Apple TV on my iPhone 15 Pro, running latest software update.

My issue is complicated but I'll try and explain as best I can.

The payment pops up with double click power button etc and I select the card via Apple Pay and confirm with Face ID. Payment seemingly confirms, order processes and film becomes available in my library.

The problem is my card is not charged, no pending payment. But instead the card that is my default for Apple ID billing (where my subscriptions etc come from) gets billed instead. I know this because the card is also in apple wallet but the transactions are not shown there, where they would be if Apple Pay was used for that card right?

I've checked with the bank for the card that i'm trying to use and they've no record of any declined payments. I've tried this with two different Apple Pay cards (chase and monzo) and on each occasion it looks to have gone through but the other card (Santander) is charged.

Anybody else experienced this? I guess best thing to do is call apple or go into a store but just wanted to ask here to see if its just my phone or if the latest update has broken Apple Pay.

Thank you.