Spot Features disappear when adding to terrain model

I'm creating terrain models from elements by selecting individual feature types (breaklines, spots, voids) and adding them.  When adding the spot features, the individual point elements are all deleted from the .dgn.  They still seem to be occupying the level, but they are no longer visible.  This is happening in Power InRoads, Power Geopak, and Open Roads Designer on both Windows 7 and Windows 10 systems.

Is this a setting that can be changed? Or is it by design?  If so, what is the purpose of deleting the elements?

Thanks,

Jason