and extracted the zip file on my C drive. I then loaded VS2019 and on the start screen I used "Open a local folder" and opened the base folder for this CMake project. Once the CMake project has loaded, and VA and the IDE have finished parsing, VA's Open File in Solution dialog is showing 13,556 files.
When I open the two files "cpp_native.cpp" and "cpp_native.hpp" VA's syntax colouring is being applied to the editor, and everything looks as expected.