HierarchicalExpanderColumn is truncated when scrolling up/down if template is composite

[perfect100]

Hi there:
I've defined a HierarchicalExpanderColumn with Template in a TreeDataGrid.
If the template is simple:

<DataTemplate x:Key="FirstColumnHeaderKey"  x:CompileBindings="False">
    <TextBlock Text="{Binding ., Converter={StaticResource TreeNodeNameConverter}}" Margin="2" />
</DataTemplate>

It works well.

However, if the template is more complicated:

<DataTemplate x:Key="FirstColumnHeaderKey" x:CompileBindings="False">
    <DockPanel VerticalAlignment="Center" HorizontalAlignment="Left" Margin="2">
        <Image Source="{Binding ., Converter={StaticResource TreeNodeIconConverter}}" Height="18" Width="18" DockPanel.Dock="Left"/>
            <TextBlock Text="{Binding ., Converter={StaticResource TreeNodeNameConverter}}" Margin="2" />
    </DockPanel>
</DataTemplate>

The TextBlock's Text has been truncated if I scroll down and then scroll up (randomly).

The fourth row content shoud be DYNAM, but sometimes DYNA OR DYN, the text is unstable.
If I resize the colum, it looks good.

The expected UI should be like this:

Does it relate to the virtualization of TreeDataGrid?

[perfect100]

So how can I bypass the issue?
Or force refresh the UI in a timer? So odd...
Any ideas?

[perfect100]

Hi @maxkatz6 , do you have any thoughts?