NavigationView content display problem

[MakesYT]

I noticed that the Frame does not obscure the TitleBarHost in the official example, but this is not the case in my own program. Does anyone know the solution?
official

<Grid RowDefinitions="Auto,*">
        <Grid Name="TitleBarHost"
              ColumnDefinitions="Auto,Auto,*,Auto" 
              Background="Transparent">
            <Image Margin="12 4"
                   IsHitTestVisible="False"
                   Source="/Assets/FAIcon.ico"
                   Width="18" Height="18"
                   DockPanel.Dock="Left"
                   Name="WindowIcon"
                   RenderOptions.BitmapInterpolationMode="HighQuality">
                <Image.IsVisible>
                    <OnPlatform Default="False">
                        <On Options="Windows" Content="True" />
                    </OnPlatform>
                </Image.IsVisible>
            </Image>

            <TextBlock Text="{Binding Title, RelativeSource={RelativeSource FindAncestor, AncestorType=Window}}"
                       FontSize="12"
                       IsHitTestVisible="False"
                       VerticalAlignment="Center"
                       Grid.Column="1">
                <TextBlock.IsVisible>
                    <OnPlatform Default="False">
                        <On Options="Windows" Content="True" />
                    </OnPlatform>
                </TextBlock.IsVisible>
            </TextBlock>
            
            <Border Grid.Column="2" Padding="6">
                <AutoCompleteBox Name="SearchBox"
                                 MaxWidth="500"
                                 Watermark="Search"
                                 Classes="SampleApp"
                                 ValueMemberBinding="{Binding Header, DataType=vm:MainAppSearchItem}"
                                 ItemsSource="{Binding SearchTerms}">
                    <!--wnd:AppWindow.AllowInteractionInTitleBar="True"-->
                    <AutoCompleteBox.ItemTemplate>
                        <DataTemplate x:DataType="vm:MainAppSearchItem">
                            <Panel>
                                <StackPanel HorizontalAlignment="Left"
                                            VerticalAlignment="Center">
                                    <TextBlock Text="{Binding Header}" />
                                    <TextBlock Text="{Binding Namespace}"
                                               Theme="{StaticResource CaptionTextBlockStyle}"
                                               Foreground="{DynamicResource AccentTextFillColorPrimaryBrush}"
                                               FontStyle="Italic"/>
                                </StackPanel>
                            </Panel>
                        </DataTemplate>
                    </AutoCompleteBox.ItemTemplate>
                </AutoCompleteBox>
            </Border>
        </Grid>

        <ui:NavigationView AlwaysShowHeader="False"
                           PaneDisplayMode="Left"
                           Grid.RowSpan="2"
                           Name="NavView"
                           IsSettingsVisible="False"
                           IsBackEnabled="{Binding #FrameView.CanGoBack}">
            <ui:Frame Name="FrameView" />
        </ui:NavigationView>

        <Panel Name="OverlayHost"
               Grid.Row="1">
            <local:ControlDefinitionOverlay Name="CtrlDefOverlay" />
        </Panel>
    </Grid>

my program

<Grid RowDefinitions="Auto,*">
        <Grid Name="TitleBarHost"
              ColumnDefinitions="Auto,Auto,*,Auto" 
              Background="Transparent">
            <Image Margin="12 4"
                   IsHitTestVisible="False"
                   
                   Width="18" Height="18"
                   DockPanel.Dock="Left"
                   Name="WindowIcon"
                   RenderOptions.BitmapInterpolationMode="HighQuality">
                <Image.IsVisible>
                    <OnPlatform Default="False">
                        <On Options="Windows" Content="True" />
                    </OnPlatform>
                </Image.IsVisible>
            </Image>

            <TextBlock Text="{Binding Title, RelativeSource={RelativeSource FindAncestor, AncestorType=Window}}"
                       FontSize="12"
                       IsHitTestVisible="False"
                       VerticalAlignment="Center"
                       Grid.Column="1">
                <TextBlock.IsVisible>
                    <OnPlatform Default="False">
                        <On Options="Windows" Content="True" />
                    </OnPlatform>
                </TextBlock.IsVisible>
            </TextBlock>
            
            <Border Grid.Column="2" Padding="6">
                <AutoCompleteBox Name="SearchBox"
                                 MaxWidth="500"
                                 Watermark="Search"
                                 Classes="SampleApp"
                                >
                    <!--wnd:AppWindow.AllowInteractionInTitleBar="True"-->
                    <AutoCompleteBox.ItemTemplate>
                        
                    </AutoCompleteBox.ItemTemplate>
                </AutoCompleteBox>
            </Border>
        </Grid>


        <ui:NavigationView Name="NavView"  PaneDisplayMode="Left" Grid.RowSpan="2"  CompactPaneLength="48"
                           ItemInvoked="NavView_OnItemInvoked" Classes="SampleAppNav" 
                           IsBackEnabled="{Binding #FrameView.CanGoBack}" AlwaysShowHeader="False"
                           BackRequested="NavView_OnBackRequested"
                           IsSettingsVisible="False">
            <ui:Frame  Name="FrameView" Navigated="FrameView_OnNavigated" />
            <ui:NavigationView.MenuItems>
                <ui:NavigationViewItem Classes="SampleAppNav" Content="主页" FontSize="30" Cursor="Hand" Tag="HomePage" />
                <ui:NavigationViewItem Classes="SampleAppNav" Content="插件" FontSize="30" Cursor="Hand"
                                       Tag="PluginManagerPage" />
                <ui:NavigationViewItem Classes="SampleAppNav" Content="情景" FontSize="30" Cursor="Hand"
                                       Tag="CustomScenariosManagerPage" />
                <ui:NavigationViewItem Classes="SampleAppNav" Content="快捷键" FontSize="30" Cursor="Hand"
                                       Tag="HotKeyManagerPage" />
            </ui:NavigationView.MenuItems>
            <ui:NavigationView.FooterMenuItems>
                <ui:NavigationViewItem Classes="SampleAppNav" Content="设置" FontSize="30" Cursor="Hand"
                                       Tag="SettingPage" />
            </ui:NavigationView.FooterMenuItems>
        </ui:NavigationView>
        <Panel  Name="OverlayHost"
               Grid.Row="1">

        </Panel>

    </Grid>

[amwx]

Sample App:

FluentAvalonia/samples/FAControlsGallery/Styling/Resources.axaml

Lines 10 to 11 in 30b4379

	<!-- Override this so content doesn't appear in title bar area -->
	<Thickness x:Key="NavigationViewContentMargin">0,48,0,0</Thickness>