Unpackaged C++-applications can't activate C#-runtime components

Steps to reproduce:

• Clone the repository
• Open the "CustomControls" sample solution
• Select CppAppUnpackaged as startup project
• Run
• The app halts with an unhandled exception during Application::Start

The error message in the UnhandledException-handler is "Cannot create instance of type 'Microsoft.UI.Xaml.Controls.XamlControlsResources' [Line: 17 Position: 37]"

Setting a breakpoint in base.h, factory_cache_entry, I think that this is related to the activation of "WinUIComponentCs.WinUIComponentCs_XamlTypeInfo.XamlMetaDataProvider".

Apparently, it's not possible currently to activate C#-components in an unpackaged Cpp-application; at least not according to the current documentation and provided samples.

Environment: Visual Studio Community 2022 17.9.4.
This happens with the NuGet packages in the versions referenced in the sample project, but also with up-to-date packages.

Update: the x86 build works as expected.

Start with the CustomControls sample and the CppAppUnpackaged startup project, reproducing the failure during Application::Start. Inspect the activation path for WinUIComponentCs.WinUIComponentCs_XamlTypeInfo.XamlMetaDataProvider, including base.h and factory_cache_entry, and compare the behavior with the working x86 build. Done means the unpackaged C++ sample can activate the C# runtime component without the reported exception.