There is an option to link bank accounts to each card within the Wallet app to view your balance and transaction history. You need to link your bank via (what I assume) is through OpenConnect. Once connected, after a couple of hours it will want me to connect it again as if I’ve never connected it. This is the same with my Flex card too. I do not have this issue with any other bank account so I assume it is Monzo and not Apple.
Steps to reproduce: Go through the stages to connect any Monzo card to Apple Wallet, wait a day or two and it will require you to re-connect again. OS: iOS 17.5 Device: iPhone 15 Pro App Version: 5.73.0
Same here! Been using Apple Pay for a few years and the only times I can remember having to re-connect my card is after getting a replacement! Not had any issues.