Why does Apple ask for my Billing Information for... well ANYTHING?

About 2 weeks ago I upgraded my separate Apple TV+ and Apple Music subscriptions to an Apple One subscription and obviously it's great to have access to all the features, as well as giving my family access too.

I've just got one glaring issue I've just discovered... When I attempt to playback anything I've already purchased on each respective store, I'm asked to enter my billing information again and a transaction is attempted against my card. Again, these are one-time purchases for movies and albums that I bought YEARS ago.

WHY AM I REQUESTED TO PAY FOR SOMETHING I'VE ALREADY PURCHASED!? ON A SUBSCRIPTION!?

Please note this does not affect ANYTHING I try to stream - ONLY purchases. Bought The Batman and Dune Part 1 on Apple TV+ last month, can't watch either of them now because I'm asked to pay and confirm my billing info, which I'm too hesitant to confirm in case of additional billings.