Strange behavour when drawing on texture

I have created texture 256x192 in script which is used for UI Image. When I am drawing line which is above texture height then is not displayed, but when I draw line which is longer than texture width then is displayed without any problem. My desired effect is to have texture which is scaled to this component.

 void Start () {
 
         AddToDiagramLineHistory(RandPontsPosition(10));
 
         texture = new Texture2D(textureWidth, textureHeight, TextureFormat.ARGB32, true);
         InitTexture(texture);
         DrawDiagramLine(texture);
 
         texture.Apply();
 
         Sprite newSprite = Sprite.Create(texture, new Rect(0, 0, textureWidth, textureHeight), new Vector2(0.5f, 0.5f), 100f);
 
         image.sprite = newSprite;
     }![alt text][1]

[1]: /storage/temp/91111-123.png