c# – How to properly render a 2D outline in Unity?

I try to render a box, but I noticed that the thickness is displayed very inconsistently:

Meaning that the line to the south might appear much thicker than the other lines (but it is not always south). The inconsistency also stays if I zoom in. How to do it properly? This is how the line renderer is used in code:

    private void InitializeOutlineRenderer()
{
    outlineRenderer = GetComponent();
    outlineRenderer.enabled = true;
    
    outlineRenderer.useWorldSpace = false;
    Vector3[] corners = new Vector3[]
    {
        new Vector3(0, 0, 0),
        new Vector3(0, 2, 0),
        new Vector3(2, 2, 0),
        new Vector3(2, 0, 0),
        new Vector3(0, 0, 0)
    };
    

    outlineRenderer.positionCount = corners.Length;
    outlineRenderer.material = new Material(Shader.Find("Sprites/Default"));
    outlineRenderer.widthMultiplier = 0.08f; 
    outlineRenderer.SetPositions(corners);
    outlineRenderer.material.color = Color.white;
}

Here is a screenshot on how it displays in the inspector: