Orthogonality of degenerate modes

I have a question about the orthogonality of degenerate modes in MODE. I am wondering how I can get orthogonal degenerate modes in mode analysis? Now it gives two degenerate fundamental modes, but it seems that the two modes are not orthogonal. I would appreciate it if you could help me with that.

Our FDE solver can give orthogonal modes, whether it is degenerated or not. To verify the orthogonality, please use Overlap to calculate their overlap, by copy one mode to the global deck.

Please visit this page for some details https://kb.lumerical.com/en/layout_analysis_eigensolver_overlap_analysis_tab.html