Describe the bug

On Windows 10 20H2 there is a theme mode call custom with allow user setting start menu theme and app theme separately. The app theme follows the start menu theme but not app theme, when I try to using <hc:ThemeResources UsingSystemTheme="True" />.

Steps to reproduce the bug

1.Using Windows 10 20H2 or later version.
2. Go to windows settings → personalization → Colors
3. Select [Custom] for [Choose your color] drop down
4. Select [Dark] for [Choose your default Windows mode]
5. Select [Light] for [Choose your default app mode]
6. Set <hc:ThemeResources UsingSystemTheme="True" /> in app.xaml for applicaiton with HandyControls
7. start application

Expected behavior

The application should show follow [Choose your default app mode] setting.
In this case it should be light mode.

Screenshots

NuGet package version

HandyControls (Custom version) 3.3.11

IDE

Visual Studio 2022

Framework type

.Net Core 3.1

Windows version

October 2020 Update (19042)

Additional context

No response