Shader is drawing wireframe(?) not sure

Hello, I’m new to shaders so I wanted to try and create a simple shader that will draw a sprite.

using the following code:

            v2f vert(appdata v) {
                v2f o;
                o.position = UnityObjectToClipPos(v.vertex);
                o.uv = v.uv;

                return o;
            }
           
            fixed4 frag(v2f i) : SV_TARGET {
            float4 color = tex2D(_MainTex, i.uv);
           
            return color;
            }

This works, but it seems the shader paints the wire frame as well ?

On the left- unity default sprite shader. on the right my shader.
4676381--440321--upload_2019-6-23_1-42-20.png

The default sprite shader is using alpha blending. Your shader probably is not.