No IAppIndexingProvider was provided

[MikeCodesDotNET]

Describe the bug
When attempting to register an AppLink on iOS, the app crashes with an System.ArgumentException having been thrown. The error message is "No IAppIndexingProvider was provided".

To Reproduce
Steps to reproduce the behavior:

1. Launch the iOS app either on a simulator or physical device
2. Navigate to the second tab (Advocates)
3. Select an Advocate (I recommend selecting Mike James)
4. The app will now crash..

Expected behavior
The app shouldn't crash as the AppIndexingProvider should have been automatically set.

Smartphone:

• Device: iPhone X
• OS: iOS 12.4

Nuget Package Versions

• Xamarin.Forms: 4.0.0.497661
• Prism.Forms: 7.1.0.431

Attempts to resolve
I read here that RegisterAppLink cannot be called from a constructor. This led me to moving the call to an 'OnNavigatedTo' method. This didn't resolve the issue, which is why I then moved the call to the Advocate Selection method. This also didn't resolve the issue.