Being told to update payment details, but details are already correct

My payment method didn't work for my icloud subscription. In settings, it prompts me to "Update Payment Details". My card is still valid and hasn't expired. Nothing has changed, so the card should still work.

I tried to remove and re-add the card, but it wouldn't let me remove it because there are subscriptions attached to it. It wouldn't let me add the card again because the card is already added.

So I don't see how to get my payments working again. Can anybody help?