In picture, right hand side long profile.
You say you are cutting up down and querying the pattern that lies horizontal ?

If I have read this right then the pattern is very regular, in fact it looks cyclic.
One clue would be to measure the ridges and see if the measuremet tied in with say ball screw pitch.

Another thought is that on that profile it will be working Y and Z can you try a sample using X and Z ?

Last thought is to post a section of code that covers one of these passes.
Don't post the whole code we only have until 2020.