There is a bug in the multi-plane roof (AC7 5005).
I use a multi-plane roof with eaves overhang. When I try to offset the edge of one of the roof’s planes, strange triangular shapes appear at both vertexes of the plane. The size of the triangles seems connected to the thickness of the roof plane. And, as a side effect, all the dimensions, associated with the vertexes of the roof plane, disappear.