Display coverage not working for all files

[RDols]

I have solution with a VisualGDB project and native Unittest project using google test. Running OpenCPPCoverage works fine. I get the correct totals and report. But zooming into the files by double clicking in the coverage window opens the file, some files don't show the red and green lines of coverage. Strange thing is sometimes the .h file shows, and .cpp file not. The behavior is stable, always the same files. Don't find what essential different between the files.

Could it be a missing include path, origin of the relative path that is different? Is it possible to enable debug output what is going wrong?

Regards,
Richard