Discrepancy in Surface.GetIsoline node


I have used the same Surface geometry and have found the central points via Curve.PointAtParamter node from: PerimeterCurves and GetIsoline. I would’ve thought that this would result to a list of points that is repeated in both lists. The only explanation I’ve found is that, one of the list of curves must be longer/shorter.

Could someone help me select a set of points with the same iso direction that is also included in the main list?

Any help is welcome. Thank you!!

See if that helps,