Zebra Artifact

I did a rebuild of a surface and it looks smooth yet there’s a strange artifact in the surface. Any ideas what has caused this? Is there a quick fix?

When I copy and paste the surface into a new document the problem disappears.

ArgoFlex7.3dm 3.zip (444.6 KB)

I figured it out, or at least I got rid of the issue using the setpt function. It’s still strange how such little faults arise. If I knew how, I’d delete this post before it wastes anyone’s time.