I am testing a non-consumable IAP on an iPhone 6s running iOS 11 GM. Whenever I tap my "Buy" button, it asks me to sign in. I tap "Sign in with existing apple ID" and enter my sandbox user details (which worked fine as of a few days ago on iOS 10).
After entering, it just goes back to the same "Sign in" screen. I tried entering a few more times and it just goes back to the same screen again. Keeps looping forever.
Is this down for anyone else?