I tried redeeming a promo code for a subscription on iOS 18.
It's a yearly subscription (the promo code is for myself in this case). This always worked before. Now on iOS 18 when I redeem the code in the App Store it just spins an activity indicator in the navigation bar for a few seconds and stops. Promo code doesn't redeem. No error message either.
Now when I try to redeem the promo code on the Mac App Store I get the following error: "You must redeem this code on a device that supports App name". This error makes sense because the app is iOS/iPadOS only. But the fact that the Mac App Store displays the App name in the error message indicates that the code is valid and should work on iOS, but it does not.