Set SelectedItem for UWP ComboBox
<p>A UWP ComboBox ItemsSource displays correctly but the SelectedItem is not selected in the list. Why is that so?</p>

<p>The XAML:</p>

<pre><code>&lt;ComboBox Name="FooComboBox" 
    ItemsSource="{x:Bind ViewModel.Foos}" 
    SelectedItem="{x:Bind ViewModel.Foo,Mode=TwoWay,Converter={StaticResource ChangeTypeConverter}}"/&gt;
</code></pre>

<p><code>ChangeTypeConverter</code> comes from <code>Template10</code></p>

<p><code>Foos</code> and the value of the property <code>Foo</code> are set in the ViewModel</p>

<pre><code>public class ViewModel : ViewModelBase
{    
    Foo _Foo = default(Foo);
    public Foo Foo { get { return _Foo; } set { Set(ref _Foo, value); } }
    public ObservableCollection&lt;Foo&gt; Foos = new ObservableCollection&lt;Foo&gt;(FooService.GetFoos());
    public ViewModel()
    {
        Foo = FooService.GetDefaultFoo();
</code></pre>

<p>A Foo looks like this</p>

<pre><code>public class Foo
{
    public Guid FooId { get; set; } = Guid.NewGuid();
    public string FooCode { get; set; }

    public override string ToString()
    {
        return FooCode;
    }
}
</code></pre>

<p>Yet although <code>FooComboBox</code> correctly renders the list of <code>Foos</code>, the  <code>SelectedItem</code> is not set to the current value of the property <code>Foo</code>. Why is that so?</p>