DataTemplate with bindable component - data-binding

Question

I have a ListView with a data template. I am trying to have a custom component that supports binding for the content of the data template.
Here is the ListView in the page:
<ListView ItemsSource="{Binding List}">
<ListView.ItemTemplate>
<DataTemplate x:DataType="entities:ListItem">
<ViewCell>
<components:ListItemView ListItem="{Binding}" />
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
And this is the ListItemView declaration:
public partial class ListItemView : StackLayout
{
public static readonly BindableProperty ListItemProperty
= BindableProperty.Create(
nameof(ListItem), typeof(ListItem), typeof(ListItemView), null,
defaultBindingMode: BindingMode.TwoWay,
propertyChanged: ListItemPropertyChanged);
static void ListItemPropertyChanged(BindableObject bindable, object oldValue, object newValue)
{
var view = (ListItemView)bindable;
view.ListItem = (ListItem)newValue;
}
public ListItem ListItem
{
get => (ListItem)GetValue(ListItemProperty);
set
{
SetValue(ListItemProperty, value);
if (_viewModel != null) // never hits this break point
_viewModel.ListItem = value;
}
}
I had a breakpoint on the line with the comment. This breakpoint was never hit. ListItemView however does get initialized and created.
Update
I tried a simple demo to ensure the issue was in the binding,
<StackLayout Padding="5">
<Label Text="{Binding Demo.Title}" />
<components:CheckListView ListItem="{Binding Demo}" />
</StackLayout>
The above code was outside the list view and I am able to see the title. The breakpoint is still not hit.