filleting problems: won't filllet an edge without leaving a surface lip from a solid part that was made by surface lofting

I'm not exactly sure why this is happening, but if someone could give some input; I would greatly appreciate it.

after I created a surface by lofting together multiple sketches, created a reference plane that correlates to the top face of the surface, converting the surface entity into a sketch, and then extruding that sketch to the surface creating a solid body: I cannot fillet the edges of the solid body fully without it leaving a lip that is the surface. why is it doing this??? grrrr