Color bleeding across pixels

My 2D image is pixel perfect when I generate it randomly and save it as a PNG, but when in code I add it to a flat “cube” I randomly get bleeding of colors. A black and white chess board type look is mixed up with green grass and blue water, see pictures.
I


My code to add the texture is:

public static void ApplyMaterialToObject(Material mat, GameObject toApplyObject)
{
    Renderer render = toApplyObject.GetComponent<Renderer>();
    if (render == null)
        return;//error
    render.material = mat;
}

Solution = had to put compression on high quality