Difficulties LineBuilder - Building a line in the correct order

Hi everyone and happy easter!

I am facing some difficulties with the LineBuilder Transformer, maybe someone has an idea how to solve this issue.

I am generalizing lines, to calculate the lenght between linepoints per line feature.

Our surveying data (especially lines) are generated based on linepoints. Anway, inbetween those linepoints lines (splines, arcs) often have vertexpoints, to display their curvature.

I managed to give all linepoints the ID of the corresponding line feature (often linepoints carry geometry for more than 1 line, because they are intersection points).

Now i need to build the simplifies lines for each line feature, but only using the linepoints as vertexpoints. In some cases it turns out well, but in other one I am achieving an interesting result (see attached pictures). Do you have any idea why my lines are in some cases built like this? Or how to avoid such results?

Picture 1: Original line feature

Picture 2: Linepoints of this line feature

Picture 3: Result of the LineBuilder