Recently, when performing an orbit in a 3D view I've noticed that some walls visually disappear even though they are still there. I've checked numerous times the VG settings to ensure walls are displaying, yet some walls remain visible and others don't when I orbit (they are not hidden). I have to "change" the discipline back again to architecture (even though it already was) and hit apply for them to reappear again.
Why is this happening? (picture below).

