B-line problem

So, I’m just learning to use this application and for some reason it will not allow me to see more than one b-line at a time, unless I highlight them together in the layers box. Could anyone tell me what might be wrong with the program?

Please be sure that you have “Composite” or “By Layer Default” on the Blend Method of the ToolBoxdefaultswhen creating a new layer.

I had it on the “By Layer Default” and I changed it to “Composite” just in case maybe something screwy was going on with mine, but it still keeps disappearing unless I highlight them on the layers section. Do you know if there is anything else it or myself could be doing wrong?

What is the outline width ? It would help us to figure out the root cause if you can upload your problem file.