Hello Nick,
This thread looks similar but was left unanswered.
Could you try to reload your CMake project? Is the source file part of the project and part of a target executable/library?
If it’s still not working, could you send us a small reproducer project so that we can have a closer look ?
Thanks
EDIT: and to answer your questions, SonarLint relies only on the CLion project to find files to analyze. It does not rely on sonar-project.properties or compilation database files.