Bug Simple Liner renderer doesn't work

Hi,
i tried to create a simple line renderer in a 2D scene. The linerenderer should draw a pentagon and is the only object in scene. The points are set manually.
In the scene editor the linerenderer has a strange appearance and when i run the scene the lines of the pentagon are dotted or invisibles.

This is how the liner renderer appears in the scene editor


This is how it appears when the scene run (It should be a white background with a pentagon with black lines)




I'm attaching the settings of the main camera and of the gameobject, anyone can tell me what I'm doing wrong or I am missing?

Main Camera Inspector


GameObject with Linerender inspector



Can anyone help me? Maybe is some wrong settings in unity also?