Problem with Trim Line with multiple Regions

Hi,

i have a collections of lines (790) and a collection of surfaces (363).

Every line has one surface at the start and end.

My wish is to trimm the lines with/on the surfaces and to keep the lines outside the surfaces.

As you can see, i get null results and somehow i can't figure out what im doing wrong.

The "Trim" component is working fine for some lines, but not for all. Why?

Thanks in advance.