I always used to select my start point in LNM and then import that the MSFS to ensure I started C&D.
But around SU8 or 9 it stopped working and still doesn’t. (my LNM version and scenery is up to date). Now I just load the flight plan from LNM to WM and select the start point from the World Map drop down (but never from the map as that will STILL result in the downloaded fligh plan being replaced by an autogen one.