TabView titlebar drag region not draggable randomly

[FrozenAssassine]

Describe the bug

The TabStripFooter does not properly serve as a titlebar, at some points of resizing the window, it just stops working and breaks.

Steps to reproduce the bug

1. Create a new WinUI3 Project
2. Add a TabView with at least enough tabs to make it scrollable:
3. Add a drag region which serves as the titlebar

<TabView
      x:Name="tabControl"
      Loaded="tabControl_Loaded">
    <TabView.TabStripFooter>
        <Grid x:Name="customDragRegion" HorizontalAlignment="Stretch" Background="Green" VerticalAlignment="Stretch" MinWidth="188" Margin="0,-2,0,0"/>
    </TabView.TabStripFooter>
</TabView>

4. Set the titlebar in the code behind:

this.ExtendsContentIntoTitleBar = true;

private void tabControl_Loaded(object sender, RoutedEventArgs e)
{
    this.SetTitleBar(customDragRegion);

    for (int i = 0; i < 20; i++)
        tabControl.TabItems.Add(new TabViewItem { Header = "Tab Header!" });
}

5. You should see a green grid in the window.
6. Start moving your window by clicking on the green grid. Should work. Now put your window into maximized mode. Moving the window does not work anymore. Putting the window back to normal size, should also not allow moving it. But resizing just a tiny bit fixes everything and moving works again.

Expected behavior

I would expect the window to always be able to get moved around

Screenshots

20250227-0656-34.6436089.mp4

NuGet package version

Windows App SDK 1.6.3: 1.6.250108002

Packaging type

Packaged (MSIX)

Windows version

Windows 11 version 24H2 (22621, October 2024 Update)

IDE

Visual Studio 2022

Additional context

No response

[github-actions]

Hi I'm an AI powered bot that finds similar issues based off the issue title.

Please view the issues below to see if they solve your problem, and if the issue describes your problem please consider closing this one. Thank you!

Closed similar issues:

• [WinUI 3] TabView as TitleBar: TabStripFooter glitches out when maximizing Window (#8878), similarity score: 0.82
• Custom Title Bar Drag Region prevents click on taskbar buttons in Fullscreen mode at certain size (#9749), similarity score: 0.82

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[FrozenAssassine]

I found a workaround, by calling the SetTitleBar function everytime my customDragRegion layout changes.

public MainWindow() {
    ...
    customDragRegion.LayoutUpdated += TitleBarGrid_LayoutUpdated;
    this.Closed += MainWindow_Closed;
}

private void MainWindow_Closed(object sender, WindowEventArgs args)
{
    customDragRegion.LayoutUpdated -= TitleBarGrid_LayoutUpdated;
}

private void TitleBarGrid_LayoutUpdated(object sender, object e)
{
    SetTitleBar(customDragRegion);
}

[snigdha011997]

From the above comments, seemingly workaround has fixed the issue for author, closing this issue, feel free to reopen if any futher questions.