Nested Docksites with ToolWindows prevents Auto-Hide support

Hello, I'm seeing a bug with nested dock sites.

I have a DockSite like the one below. In the example, the outermost ToolWindow will expand when the mouse is hovered over. The inner (nested) ToolWindow will not expand, and cannot be opened in any way by the user.

My expectation is that each ToolWindow responds to the mouse hover on its tab by expanding out and displaying the content of the window.

In my application (a more complex variant of the below), a requirement is that we have nested dock sites supporting tool windows both at the outer level, and within each document window, both potentially auto-hidden.

<docking:DockSite Margin="5,5,0,0" x:Name="dockSite" CanDocumentWindowsRaft="True" Padding="0,0,0,1">
   <docking:DockSite.Switcher>
      <docking:SimpleSwitcher />
   </docking:DockSite.Switcher>

   <docking:Workspace>
      <docking:TabbedMdiHost>
         <docking:TabbedMdiContainer>
            <docking:DocumentWindow Title="Test Document">
               <DockPanel>
                  <docking:DockSite>
                     <docking:ToolWindowContainer>
                        <docking:ToolWindow Title="Test Nested Panel">
                           <TextBlock Text="Nested ToolWindow content" />
                        </docking:ToolWindow>
                     </docking:ToolWindowContainer>
                  </docking:DockSite>
      
                  <TextBlock Text="DocumentWindow Content goes here."/>
               </DockPanel>
            </docking:DocumentWindow>
         </docking:TabbedMdiContainer>
      </docking:TabbedMdiHost>
   </docking:Workspace>
   
   <docking:DockSite.AutoHideLeftContainers>
      <docking:ToolWindowContainer>
         <docking:ToolWindow Title="Test Panel">
            <TextBlock Text="ToolWindow Content goes here." />
         </docking:ToolWindow>
      </docking:ToolWindowContainer>
   </docking:DockSite.AutoHideLeftContainers>
</docking:DockSite>