Mapsui MapView blank in .Net Maui

Question

I have a strange issue. I want to Create a ContentView with a Mapsui MapView in it. But when I do this, the MapView is displayed but it is blank.

This is obviously wrong.

Here is a simple version of the issue:

MapView.xaml

<?xml version="1.0" encoding="utf-8" ?>
<ContentView xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:mapsui="clr-namespace:Mapsui.UI.Maui;assembly=Mapsui.UI.Maui"
             x:Class="MauiApp7.Pages.MapView">

    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition></RowDefinition>
            <RowDefinition></RowDefinition>
        </Grid.RowDefinitions>
        <Button Text="Get Location" Grid.Row="0" Clicked="GetLocationAsync" ></Button>
        <mapsui:MapView x:Name="_mapView"
                    AbsoluteLayout.LayoutBounds="0,0,1,1"
                    AbsoluteLayout.LayoutFlags="All"
                    VerticalOptions="FillAndExpand"
                    HorizontalOptions="FillAndExpand"
                    BackgroundColor="Gray" 
                        Grid.Row="1"/>
    </Grid>
</ContentView>

MapView.xaml.cs

using Mapsui.UI.Maui;
using MauiApp7.Pages.ViewModels;

namespace MauiApp7.Pages;


public partial class MapView : ContentView
{
    public MapViewModel ViewModel => BindingContext as MapViewModel;

    public MapView()
    {
        BindingContext = ServiceProvider.GetService<MapViewModel>();
        _mapView = new Mapsui.UI.Maui.MapView();
        _mapView.Map.Layers.Add(Mapsui.Tiling.OpenStreetMap.CreateTileLayer());
        InitializeComponent();
        
    }
    private async void GetLocationAsync(object sender, EventArgs EventArgs)
    {
        //Do something
    }
}

Then, to simplify things, I just set the content in MainPage to a map view: MainPage.xaml.cs

public partial class MainPage : ContentPage
{
    public MainPage()
    {
        InitializeComponent();
        var map = new Pages.MapView();
        Content = map;
    }
}

I can't understand why this is.

If I set the MainPage.xaml.cs content directly to a

Mapsui.UI.Maui.MapView();

then that works. Like this:

public partial class MainPage : ContentPage
{
    public MainPage()
    {
        InitializeComponent();
        var mapView = new Mapsui.UI.Maui.MapView();
        mapView.Map?.Layers.Add(Mapsui.Tiling.OpenStreetMap.CreateTileLayer());
        Content = mapView;
    }
}

then I get my map correctly displayed.

Any thoughts on this?

Thanks!