Well I looked at it and I can't figure out for the life of me what you have managed to do.

I checked the geo, I deleted history, I cleaned zombie nodes, I exported to obj and back in again.

It smooth previews fine, I can explicitly smooth it and in the gui it looked fine but when you render with contour rendering on it gets a bunch of extra edges and I have no clue why.


Also you modeled the entire thing rotated off axis so it was an extra pain when I tried to cut the model in half and then mirror it to see if I could clean it up. As far as I can tell the geo looks valid but there has to be something that is not showing up when I look at the hypergraph that is messing up the contour render.

I'd wait and see if anyone can figure it out and if not it might be faster to get things back to proper axis alignment, delete that part and remodel it CAREFULLY.