"This file is not part of any project" warning on qmake projects before manually launching qmake

Hello,

With a qmake project, I'm currently getting a warning saying "This file is not part of any project" whenever I launch a C++ qmake project and going to a file (for example a .cpp one).

The error seems to go away if I manually launch qmake through Build > run qmake.

One comment worth noting is that my qmake project has a root .pro file with:

CONFIG += ordered
TEMPLATE = subdirs
SUBDIRS += ImagePlugin MyApp

Then MyApp/MyApp.pro is very standard:

TEMPLATE = app

QT += qml quick
CONFIG += c++17
CONFIG += qtquickcompiler

SOURCES += [...]
HEADERS += [...]

I am not using the experimental clangd for the moment, only the Clang Code Model. Qt version used by the project is 5.14.1.

Thank you,
Best regards,
Louis