Code model finds header but editor does not

[ferdymercury]

I have a C++ CMake project that I open with QtCreator. When I open one file related to this project, but located outside the source code, it gives me a warning saying that the code model might have issues parsing the file. However, when I open the C++ CodeModel with CTRL-Shift-F12, it correctly finds all headers, see image below.

Does someone now why this happens?

More info: https://root-forum.cern.ch/t/qt-creator-confusing-header-file-warnings/52398