IOS In app purchase problem

We are almost done developing our app, and just have the issue of in-app purchases on IOS. We have successfully implemented the in-app purchases on Android, and are struggling to achieve the same result on IOS.

After reading through seemingly every post on the subject, we know we have to have these in our config file:

[OnlineSubsystem]
;DefaultPlatformService=GooglePlay
DefaultPlatformService=IOS

[DeviceProfileManager]
DeviceProfileSelectionModule="IOSDeviceProfileSelector"
 
[OnlineSubsystemIOS.Store]
bSupportsInAppPurchasing=True

And we have also added this to our build.cs:

if (Target.Platform == UnrealTargetPlatform.Android)
        {
            PrivateDependencyModuleNames.AddRange(new string[] { "OnlineSubsystem", "OnlineSubsystemGooglePlay" });
        }
        else if (Target.Platform == UnrealTargetPlatform.IOS)
        {
            PrivateDependencyModuleNames.AddRange(new string[] { "OnlineSubsystem", "OnlineSubsystemIOS" });
        }

When we use the Make an In-App Purchase node in blueprints, absolutely nothing happens on IOS. As far as we can tell, it passes right through the OnSuccess and OnFailure events without triggering either. The exact same setup triggers the store page on Android, and we are unsure where the problem is for IOS. I have attached our blueprint setup below. Any help would be appreciated.

It is also important to note that we know the online subsystem is working on IOS, because the achievements are functioning properly with game center.