Unable to unlock IAP in iOS app with promo code

Do we have to put any special code in an iOS app in order to unlock the in-app purchases via a promo code?

We have an app containing a single “Full Version” IAP (implementing iap_badger). When a redeem a promo code for this IAP through the App Store, I get an App Store message saying that I have been successfully credited the “Full Version”.

After redeeming, I launch the app (which was already installed on the device) and I get this popup message “There is no information available for In-App Purchases. Try again later. 21105”. The content of the IAP is still locked inside the app. 

Does the app need any special code to support IAP unlock via promo codes? Thanks!