MAUI Grouped ListView Remove Item Causes Error when more than one Group item exists

[PBlaa]

Description

I have a grouped list in C# MAUI MVVC, destination is Andoid

public class GroupData : ObservableCollection<DetailData>
{
    public string Name { get; private set; }
    public GroupData(string name, ObservableCollection<DetailData> d) : base(d) 
              { Name = name; }
}

public class DetailData
{
    public int Nr { get; set; }
    public string Detail { get; set; }
}

Test data are added like this

public ObservableCollection<GroupData> GetData()
{
    ObservableCollection<GroupData> data = new ObservableCollection<GroupData>();

    data.Add(new GroupData("Group1", new ObservableCollection<DetailData>
    {
        new DetailData { Nr = 1, Detail = "Test 1" },
        new DetailData { Nr = 2, Detail = "Test 2" }
    }));

    data.Add(new GroupData("Group2", new ObservableCollection<DetailData>
    {
        new DetailData { Nr = 3, Detail = "Test 3" },
        new DetailData { Nr = 4, Detail = "Test 4" }
    }));

    return data;
}

Main Page View Model has the bindable collection

public ObservableCollection<GroupData> GroupData { get; } = new ObservableCollection<GroupData>();

and an event on a button when showing the list.
Clicking on it should remove the selected item.

[RelayCommand]
private async Task ButtonOk(DetailData data)
{
    foreach (var item in GroupData)
    {
        foreach (var child in item)
        {
            if (child.Nr == data.Nr)
            {
                item.Remove(child);
                break;
            }
        }
    }
}

Data are shown with this

<RefreshView Command="{Binding RefreshCommand}" IsRefreshing="{Binding IsBusy, Mode=TwoWay}">
    <ScrollView>
        <Grid>
            <ListView ItemsSource="{Binding GroupData}" 
                      IsGroupingEnabled="True"
                      HasUnevenRows="True">
                <ListView.GroupHeaderTemplate>
                    <DataTemplate x:DataType="daten:GroupData">
                        <ViewCell>
                            <Label Text="{Binding Name}"/>
                        </ViewCell>
                    </DataTemplate>
                </ListView.GroupHeaderTemplate>
                <ListView.ItemTemplate>
                    <DataTemplate x:DataType="daten:DetailData">
                        <ViewCell>
                            <Grid >
                                <Label Text="{Binding Detail}"/>
                                <ImageButton Source="ok.jfif"
                                    Command="{Binding Source={RelativeSource AncestorType={x:Type local:MainPageViewModel}}, 
                                    Path=ButtonOkCommand}" 
                                    CommandParameter="{Binding .}"/>
                            </Grid>
                        </ViewCell>
                    </DataTemplate>
                </ListView.ItemTemplate>
            </ListView>
        </Grid>
    </ScrollView>
</RefreshView>

Now, when adding ONLY ONE grouped item to the observable collection "Group 1" with the two childs the removing works perfect.

But when adding a SECOND "Group 2" it unfortunately fails with error

Java.Lang.IllegalStateException: 'The specified child already has a parent. You must call removeView() on the child's parent first.'

Steps to Reproduce

see code and description

Link to public reproduction project repository

No response

Version with bug

8.0.93 SR9.3

Is this a regression from previous behavior?

No, this is something new

Last version that worked well

No response

Affected platforms

Android

Affected platform versions

No response

Did you find any workaround?

remove

<RefreshView >
    <ScrollView>

Relevant log output

[dotnet-policy-service]

Hi @PBlaa. We have added the "s/needs-repro" label to this issue, which indicates that we require steps and sample code to reproduce the issue before we can take further action. Please try to create a minimal sample project/solution or code samples which reproduce the issue, ideally as a GitHub repo that we can clone. See more details about creating repros here: https://github.com/dotnet/maui/blob/main/.github/repro.md

This issue will be closed automatically in 7 days if we do not hear back from you by then - please feel free to re-open it if you come back to this issue after that time.

[dotnet-policy-service]

This issue has been automatically marked as stale because it has been marked as requiring author feedback to reproduce the issue but has not had any activity for 4 days. It will be closed if no further activity occurs within 3 days of this comment. If it is closed, feel free to comment when you are able to provide the additional information and we will re-investigate.