I used to use lineRenderer.SetWidth() before upgrading to Unity 5.5.1f1 and it was working well.
I upgraded and changed this code:
lineRenderer.SetWidth(scale, scale);
to next:
lineRenderer.startWidth = scale;
lineRenderer.endWidth = scale;
It works, but not always. A value in Inspector changes, but it doesn’t get reflected in Game. When I update the value to the same (without changing it) in Inspector, it gets reflected. It feels like a bug.
Note: I enable/disable Line Renderer components in Game at runtime.