CMake include_directories ignored for subprojects except for the first one

I have a project consisting of 4 sub projects. They are all added in the Main project's CMakeLists.txt with add_subdirectory and then each sub project uses include_directories to sets its include paths.
Qt Creator source code editor fails to see these paths and claims that the included files are not found for all files in paths defined bu second third and fourth sub projects.
Code model also shows only the pats added in the first sub project.
Building works but in editor there are lots of warnings because of this.
Maybe an indexer issue?
This seems like a regression, it happened before in the early 3.x versions