I noticed that too.
The issue is that there's incorrect geometry in the alignment. My previous implementation was just more tolerant of that than the current one is. I considered trying to make it better, but then I decided not to, because if the geometry is incorrect, then the user needs to fix it anyway.
Anyway, the proper course of action would be for the user to go into the horizontal alignment design tool and fix the geometry there (when I get it done ), or fix it outside of FreeCAD and re-import.