Disappearing corners and reference lines

[Kamelite]

How come this happens? I discovered that if the inner and outter walls have the reference line on the same side, i.e. the thick wall on its outside, and the thin wall on its inside, so that the reference line was right next to each other, the corners get all messed up. This happens regardless of it beeing an inside corner or an outside corner, although it looks different when it comes to inner corners. Changing the reference line on the outter square of walls to its outside, solved the whole problem.

So, here comes the million $ question: Bug or feature? In case of feature, why does it happen??

.Kamelite

[Laszlo Nagy]

Maybe a side effect.
See, in every corner, there are two overlapping Wall Reference Lines coming from both directions. So I think ARCHICAD just decides randomly which joining Wall to use.

As a rule of thumb, I never model my Walls so that such a scenario occurs, because as you can see, it may lead to unpredictable results.