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?
The same thing happens for me, for three separate sandbox users which were created before iOS 11 release. (The problem seems prevalent on iOS 11, there are posts on reddit and apple forums reporting this issue)
It seems creating new fresh sandbox user is the way to go. Sandbox users created after iOS 11 release work, while those created before the release cause "Sign in/Create Apple id" alert loop.