Ive ditched farmer boys version of SSC and your “old” version works wonders. Just sucessfully completed my longest road which is the length of the map up and down hills!
However, just hit the same problem again on a second “off shoot” road.
The road starts flat then goes up an initial incline.
The road at the top of the incline is fine but every now and again a road tile gets flipped 180 degrees aswell.
Checked through the .i3d and aall axis are showing 0.