Waterline in wrong order

I cut out this job in aluminium. I use a step down of 0.18mm.
The first pass for each segment is -0.18 but the second is -0.90. Then again it is correct with -1.08 and so on. The missing passes is done last and in backward order…
So the order is:


This big steps caused alot of noice but luckely the machine could handle it so I did not loose the job. Anyone have any ideas why it behaves like this? I’m not allowed to upload the project files but can mail it to anyone that knows how to examen them.

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