Can't change Hierarchical Navigation

Hi,

I'm 100% new to Xamarin.

I've downloaded the sample code from the Xamarin developer website (sorry, can't post link). When I edit that code, I can't make page 1 navigate to page 3. When I replace:

    async void OnNextPageButtonClicked (object sender, EventArgs e)
    {
        await Navigation.PushAsync (new Page2 ());
    }

With

    async void OnNextPageButtonClicked (object sender, EventArgs e)
    {
        await Navigation.PushAsync (new Page3 ());
    }

and I debug, the "Next Page" button on page 1 still links to page 2. I've spent 1 hour trying all sorts of solutions and I'm lost. Can you help?

Thanks and best regards,

Carl Juneau, PhD