No header (title) is shown for a LayoutAnchorable

Version: 4.51.1 Visual studio 2019 and .Net 5.0

Consider the following simple MWE

<Window x:Class="Dirkster99AvalonDock.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:ad="https://github.com/Dirkster99/AvalonDock"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:local="clr-namespace:Dirkster99AvalonDock"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        Title="MainWindow"
        Width="800"
        Height="450"
        mc:Ignorable="d">
    <Grid>
        <ad:DockingManager x:Name="dockManager">
            <ad:LayoutRoot>
                <ad:LayoutPanel Orientation="Vertical">
                    <ad:LayoutDocumentPane>
                        <ad:LayoutDocument Title="doc" CanFloat="True">
                            <Border Background="AliceBlue" />
                        </ad:LayoutDocument>
                    </ad:LayoutDocumentPane>
                    <ad:LayoutAnchorablePane DockHeight="100">
                        <ad:LayoutAnchorable Title="anchorable">
                            <Border Background="Gold" />
                        </ad:LayoutAnchorable>
                    </ad:LayoutAnchorablePane>
                </ad:LayoutPanel>
            </ad:LayoutRoot>
        </ad:DockingManager>
    </Grid>
</Window>

The result is As shown above, the header of the LayoutAnchorable is not shown, which is supposed to display the title. Is this a bug, or did I miss anything?

[NOTE] If I simply change the avalon dock to the one in xceed wpftookit, then the title of the anchorable pane is shown as expected.

[ShuhuaGao]

Update

The previous version v4.50.3 on NuGet has no problem. Thus, a bug was introduced after v4.50.3.

The following screenshot was obtained with v4.50.3

[dfraska-ftl]

Here’s the workaround that worked for me, since it wasn’t very clear from the previous comments:

In app.xaml:

Add the namespace

    xmlns:avalon="https://github.com/Dirkster99/AvalonDock"

Then, create a default style for the AnchorablePaneTitle based on AnchorablePaneTitleStyle

    <Application.Resources>
        <ResourceDictionary>
            <ResourceDictionary.MergedDictionaries>
                <ResourceDictionary Source="/AvalonDock;component/Themes/generic.xaml"/>
            </ResourceDictionary.MergedDictionaries>
            <Style TargetType="{x:Type avalon:AnchorablePaneTitle}"
                   BasedOn="{StaticResource AnchorablePaneTitleStyle}"/>
        </ResourceDictionary>
    </Application.Resources>