Could someone else test this to confirm whether it’s a bug…
1: Open Apple Wallet app.
2: Tap your Starling card.
3: Tap the tiny Starling logo at the bottom left.
Has Touch ID now been disabled in the Starling app? If so, you will need to use your PIN to login to the Starling app and then re-enable Touch ID?
Seems to happen every time for me.