x:Bind to built-in control ActualTheme fails to compile in C++

[HO-COOH]

Describe the bug

The exact code works in C#.
Obviously in C++, it generates the wrong code. For example, if I have <TextBlock Text="{x:Bind local:MyPage.ElementThemeToString(MyButton.ActualTheme), Mode=OneWay}" />, it generates

        void DependencyPropertyChanged(DependencyObject const& sender, DependencyProperty const& prop) override
        {
            if (sender)
            {
                if (sender == cacheDPC_MyButton_ActualTheme && ::winrt::Microsoft::UI::Xaml::Controls::Button::ActualThemeProperty() == prop)

The ActualThemeProperty() is in FrameworkElement not in Button, so it fails.

Curiously, {x:Bind} to my custom UserControl compiles fine, generates the correct code.

Steps to reproduce the bug

1. Create a C++ packaged project
2. Create a new Page (in case you say it's because of Window), Use this xaml

    <StackPanel>
        <Button x:Name="MyButton" />
        <TextBlock Text="{x:Bind local:MyPage.ElementThemeToString(MyButton.ActualTheme), Mode=OneWay}" />
    </StackPanel>

in code behind, simply return a string

        static winrt::hstring ElementThemeToString(winrt::Microsoft::UI::Xaml::ElementTheme theme)
        {
            switch (theme)
            {
                case winrt::Microsoft::UI::Xaml::ElementTheme::Dark: return L"Dark";
                case winrt::Microsoft::UI::Xaml::ElementTheme::Light: return L"Light";
                default: return L"Default";
            }
        }

3. Build the project

Expected behavior

No response

Screenshots

No response

NuGet package version

WinUI 3 - Windows App SDK 1.6.5: 1.6.250205002

Windows version

Windows 11 (24H2): Build 26100

Additional context

No response