System.AppContext.SetSwitch("Switch.System.Windows.Controls.ItemsControlDoesNotSupportAutomation", true);

var accessibilitySwitches = Type.GetType("System.Windows.AccessibilitySwitches, WindowsBase, Version=8.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089");
var field = accessibilitySwitches.GetField("_ItemsControlDoesNotSupportAutomation", System.Reflection.BindingFlags.NonPublic | System.Reflection.BindingFlags.Static | BindingFlags.DeclaredOnly);
field.SetValue(null, 1);

public static void VerifyMainWindowAccessibility()
{
    AutomationElement mainWindow = AutomationElement.RootElement.FindFirst(TreeScope.Children, new PropertyCondition(AutomationElement.NameProperty, "MainWindow"));
    Debug.WriteLine(DumpUIATree(mainWindow));
}

private static string DumpUIATree(AutomationElement element)
{
    var s = element.Current.Name + " : " + element.Current.ControlType.ProgrammaticName;
    DumpChildrenRecursively(element, 1, ref s);
    return s;
}

private static List<AutomationElement> GetChildNodes(AutomationElement automationElement)
{
    var children = new List<AutomationElement>();
    TreeWalker walker = TreeWalker.ControlViewWalker;
    AutomationElement child = walker.GetFirstChild(automationElement);
    while (child != null)
    {
        children.Add(child);
        child = walker.GetNextSibling(child);
    }
    return children;
}

private static void DumpChildrenRecursively(AutomationElement node, int level, ref string s)
{
    var children = GetChildNodes(node);
    foreach (AutomationElement child in children)
    {
        if (child != null)
        {
            for (int i = 0; i < level; i++)
                s += "-";
            s += " " + child.Current.Name + " : " + child.Current.ControlType?.ProgrammaticName + "\r\n";
            DumpChildrenRecursively(child, level + 1, ref s);
        }
    }
}

public class Program
{
    [STAThread]
    static void Main()
    {
        AppContext.SetSwitch("Switch.System.Windows.Controls.ItemsControlDoesNotSupportAutomation", true);

        var app = new App();
        app.InitializeComponent();
        app.Run();
    }
}