'S' Symbol showing up in Foundation views

[Dave.M]

Help
I am getting this 'S' symbol showing up in my foundatoin plan and 3D views that won't go away. I recall reading a little about what it stands for in other posts but cant remember is the is a way to get rid of it. Its like it causes the footer of a shallower area of the total foundation (like the crawl space) to creep down the wall of the deeper basement walls. Any help appreciated.
(See Pics)