Done button not firing completed event on Entry

I have used the Xamarin example of adding a Done button to a numeric keyboard however this is not firing the Entry Completed event.

I can see that the delegate is being executed when the done button is pressed but how can I get a notification to my view that the Done button was pressed?

I used this example: https://developer.xamarin.com/recipes/cross-platform/xamarin-forms/add-done-to-keyboard/