What event do I need to make the verticle scrollbar visible?

I have my custom renderer for the ListView control and the intention is that the scrollbar is always displayed.
According to the Android documention this can be done;
https://developer.android.com/reference/android/view/View#setVerticalScrollBarEnabled(boolean)
However my custom control does not do this as intended. The Scrollbar behaves as before, not visible unless a ListView item is selected.
What am I doing wrong?

                <c:ListViewScrollBar ItemsSource="{Binding PropertyList}">
                    <c:ListViewScrollBar.Behaviors>
                        <b:EventToCommandBehavior Command="{Binding ItemTappedCommand}"
                                                  EventName="ItemTapped"
                                                  EventArgsParameterPath="Item" />
                    </c:ListViewScrollBar.Behaviors>
                    <c:ListViewScrollBar.ItemTemplate>
                        <DataTemplate>
                            <ViewCell>
                                <ContentView  Padding="3">
                                    <Label Text="{Binding FullAddress}" BackgroundColor="blue" TextColor="White" FontSize="7"
                                           VerticalTextAlignment="Center" HorizontalTextAlignment="Center" />
                                </ContentView>
                            </ViewCell>
                        </DataTemplate>
                    </c:ListViewScrollBar.ItemTemplate>
                </c:ListViewScrollBar>

using Xamarin.Forms;

namespace Sir.Mobile.CustomRenderers
{
    public class ListViewScrollBar : ListView
    {
        public ListViewScrollBar()
        {
        }
    }
}

using Android.Content;
using Sir.Mobile.CustomRenderers;
using Sir.Mobile.Droid.CustomRenderers;
using System.ComponentModel;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;

[assembly: ExportRenderer(typeof(ListViewScrollBar), typeof(ListViewScrollBarRenderer))]

namespace Sir.Mobile.Droid.CustomRenderers
{
    /// <inheritdoc />
    public class ListViewScrollBarRenderer : ListViewRenderer
    {
        public ListViewScrollBarRenderer(Context context) : base(context)
        {
        }

        protected override void OnElementChanged(ElementChangedEventArgs<ListView> e)
        {
            base.OnElementChanged(e);

            if (Control != null)
            {
                Control.VerticalScrollBarEnabled = true;
            }
        }

        protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
        {
            base.OnElementPropertyChanged(sender, e);
            if (Control != null)
            {
                Control.VerticalScrollBarEnabled = true;
            }
        }
    }
}