Neponyatki with markup. (RimWorld)

When you choose to build the walls and click the mouse for marking, it is marked as not usually square, but only the horizontal strip, in General the square is marked only on one side. When doing simple markup, or is there a roof to hang on, Yes, anything that you can lay out the square - everything works except the walls.
Similar can be observed when building the wall, and on the way there, mud, soft ground, well, like vanity, then you marking the wall in places, but other places are drawn here the same thing, but not drawn with all sides except one. Formation on the heavy ground, about it do not write,just as an example resulted.