Shatter alters polyline

The “Shatter” component seems to alter my polyline :
vertices that are colinear with their two neighbors are culled, which is not what I want.

Shatter alters (14.1 KB)

Why is this so and how can I avoid this ?

Using Bounds and Subcurve I still get missing points:

Note also that your original polyline has 184 points, only 66 of which are actually different. The polyline as a whole goes back and forth three times, you can see this using a Point On Curve slider.

This is very suspicious, and it means your curve closest point parameters could be any one of three distinct values each.

If I clean up the polyline to not self-intersect twice along its entire length, the missing point problems seems to go away: Shatter alters (13.5 KB)

I realized this also.
I’m sorry I wasted your time on this.

Thanks David