offset component acts up

I am redoing one of the earlier GH definitions for a class I am working on, it is the paneling def that lays out triangles that then can be tabbed for fabrication.

with GH 8 the offset seems to behave weird, see attached images.

How come most of the lines ( but not all ) ofset to the outside where as systematically a few lines offset to the inside?

I checked the direction ( after baking ) of the original triangles, and they seem all the same.

adding planes to it doesn't seem to help, nor does setting individual planes for all the segments ( 3 point with the origin each time being the centerpoint of the triangles )

is this abnormal behavior or am I missing something between GH7 and 8 ?