Multiple Palette for each different category of nodes

I am using GoXam Palette and diagram controls in my WPF application, which is using Prism and Mvvm frameworks.
in my control for toolbox window, i want to show multiple palettes in a listbox/ItemsControl, and i am binding Palette.Model in Xaml, as shown below
Xaml :

<ListBox x:Name="itemsControl" ItemsSource="{Binding Path=Categories}" >
        <ListBox.ItemTemplate>
            <DataTemplate>
                <StackPanel DataContext="{Binding}" Orientation="Vertical">                
                    <TextBlock Text="{Binding Path=Name}" />
                    <go:Palette  Height="200"
                Padding="10" BorderBrush="Gray" BorderThickness="1"
                HorizontalContentAlignment="Left"
                VerticalContentAlignment="Top"
                NodeTemplate="{StaticResource MyNodeTemplate}"                                
                Model="{Binding Path=PaletteModel}">
                        <go:Diagram.Layout>
                            <go:GridLayout Sorting="Forward" CellSize="5 5" />
                        </go:Diagram.Layout>
                    </go:Palette>
                </StackPanel>
            </DataTemplate>
        </ListBox.ItemTemplate>
    </ListBox>   
Model:
public class ToolBoxViewModel :BindableBase
    {
public ObservableCollection<CategoryPaletteModel> Categories { get; set; }
.
.
.
.
.
}
    public class CategoryPaletteModel : BindableBase
    {
        private string _Name;
        public string Name { 
            get {
            return _Name;
            }
            set
            {
                SetProperty(ref this._Name, value);
            }
        }

        private GraphLinksModel<MyNodeData, string, string, MyLinkData> _PaletteModel;
        public GraphLinksModel<MyNodeData, string, string, MyLinkData> PaletteModel 
        {
            get
            {
                return _PaletteModel;
            }
            set
            {
                SetProperty(ref _PaletteModel, value);
            }
        }

    }

it is executing, and showing multiple Palettes in a list, but the problem is it is not showing nodes in it. although all node items are correctly being populated into the Categories[n].PaletteModel
The strange thing is when i bring Palette control out of ListBox/ItemsControl, and showing only one Palette, it is showing all nodes into the palette.
Please help me in fixing this issue.

Each Diagram starts with a default Diagram.Model that is a UniversalGraphLinksModel, so that you can data bind Diagram.NodesSource and Diagram.LinksSource, or so that you can do other initialization of the model without having set or bound the Diagram.Model.

So one solution would be for you to data bind the Diagram.NodesSource property.

If you really want to bind the Diagram.Model property, set Diagram.HasDefaultModel to false.

Great!
it is working by setting HasDefaultModel=“False”