I have an exterior floor representing a concrete pad. I have the level set to a platform level up above my finished floor level. It works fine if the floor is flat, but as soon as I set a slope-defining line to make the floor slope 1 : 50 away from the building, the floor drops down to the finished floor level. Why is this happening? I sketched the floor in the finished floor level plan view. Do I have to sketch it from a platform level plan view to make it work correctly? Is this a bug?