XAML Binding warnings when using commands and AncestorType

I have a small MAUI program using CollectionView - and per item, there are buttons attached with a command (like changeitem)

The app is working. But I am getting warnings at compile and runtime about data binding.

            <CollectionView.ItemTemplate>
            <DataTemplate x:DataType="model:CheckItem">
                <Grid ColumnDefinitions="*,Auto" ColumnSpacing="{StaticResource StdSpacing}">
                    <Grid
                        Grid.Column="1"
                        Margin="{StaticResource StdMargin}"
                        ColumnDefinitions="auto,auto"
                        ColumnSpacing="{StaticResource StdSpacing}">
                        <Button
                            Grid.Column="0"
                            Command="{Binding Source={RelativeSource AncestorType={x:Type viewmodel:OverviewViewModel}}, Path=ChangeItemCommand}"
                            CommandParameter="{Binding .}"
                            Style="{x:StaticResource GoogleFont}"
                            Text="{x:Static font:GoogleIconFont.Edit}" />
                    </Grid>
                </Grid>
            </DataTemplate>
        </CollectionView.ItemTemplate>

The commands are located in the ViewModel viewmodel:OverviewViewModel whereas the data model for an item is located in model:CheckItem.

The ContenPage starts with

x:Class="BicycleCheckList.OverviewPage"
xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
xmlns:font="clr-namespace:BicycleCheckList.Utils"
xmlns:local="clr-namespace:BicycleCheckList.Resources.Strings"
xmlns:model="clr-namespace:BicycleCheckList.Models"
xmlns:utils="clr-namespace:BicycleCheckList.Utils"
xmlns:viewmodel="clr-namespace:BicycleCheckList.ViewModels"
Title="{Binding Title}"
x:DataType="viewmodel:OverviewViewModel">

On Compile time, I am getting a warning: XC0045 Binding: Property "ChangeItemCommand" not found on "BicycleCheckList.Models.CheckItem".

The binding of the command Command="{Binding Source={RelativeSource AncestorType={x:Type viewmodel:OverviewViewModel}}, Path=ChangeItemCommand}" does not find the command.

Why?

The (toy) app is also available on Github

While it looks somewhat redundant, you can specify the x:DataType of the binding. I believe all you need to do is change your Button declaration to:

<Button
    Grid.Column="0"
    Command="{Binding x:DataType=viewmodel:OverviewViewModel, Source={RelativeSource AncestorType={x:Type viewmodel:OverviewViewModel}}, Path=ChangeItemCommand}"
    CommandParameter="{Binding .}"
    Style="{x:StaticResource GoogleFont}"
    Text="{x:Static font:GoogleIconFont.Edit}" />

(I would normally put x:DataType at the end, but then it wouldn't be visible without scrolling...)