When I trying to build of lines from points, I get some thing like this:

I am using LineBuilder, and group by attribute (each group of points has a different name), but I don't understand why I also get connect line (green one) between them ?
When I trying to build of lines from points, I get some thing like this:

I am using LineBuilder, and group by attribute (each group of points has a different name), but I don't understand why I also get connect line (green one) between them ?