UWP HandwritingView can be enabled only for English

Question

As mentioned in this page, the UI control - HandwritingView, can be built into textbox.

To test this feature, I wrote a UWP app as below:

<Page 
    Loaded="onPageLoaded"
    x:Class="hwv.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:local="using:hwv"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d"
    Width="1440"
    Height="1300"
    Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

    <Grid>
        <TextBox x:Name="tbHandWriteView" HorizontalAlignment="Center" Margin="0,0,0,0" FontSize="60" TextWrapping="Wrap" Text="" VerticalAlignment="Top" Width="1300" Height="1200" FontFamily="Segoe UI"/>
    </Grid>
</Page>

public MainPage()
{
    this.InitializeComponent();
}

private void onPageLoaded(object sender, RoutedEventArgs e)
{
    tbHandWriteView.IsHandwritingViewEnabled = true;
    tbHandWriteView.HandwritingView.InputDeviceTypes = Windows.UI.Core.CoreInputDeviceTypes.Touch | Windows.UI.Core.CoreInputDeviceTypes.Pen | Windows.UI.Core.CoreInputDeviceTypes.Mouse;
    tbHandWriteView.HandwritingView.PlacementAlignment = HandwritingPanelPlacementAlignment.TopLeft;
    tbHandWriteView.HandwritingView.Width = 1300;
    tbHandWriteView.HandwritingView.Height = 500;
    tbHandWriteView.HandwritingView.Visibility = Visibility.Visible;

    bool bOpenHandWriteInTb = tbHandWriteView.HandwritingView.TryOpen();
}

It goes well when English (United States) is adopted as current keyboard input language. In the end of the above code, TryOpen() method will return true, and I can do handwrite and recognition in the textbox, as expected.

However, when I switch to other keyboard input language, such as Japanese and Chinese, TryOpen() method will return false without any information. The HandwritingView UI will be unavailable, and then just turn into a normal textbox.

In System Settings, the handwriting packages had been already installed for Japanese and Chinese, as screenshot here.

I have also tried Language property of UI controls: tbHandWriteView.Language = "ja-JP"; tbHandWriteView.HandwritingView.Language = "ja-JP"; , but my problem is still there.

Thanks in advance if any idea.