unity – Problem with hard edges alpha channel in sprite Shader

I was looking for a shader that could apply a texture to the sprite and place it in a mosaic according to its global position.
I found an example of shader from here.

It works fine, except that the alpha channel breaks and the edges become sharp:Left - with standard Sprites-Default shader.Right - with mine

Left – with standard default Sprite-Shader.
Right – with mine

My current shader:

Shader "Custom / Tile" {
_NewTex ("Texture", 2D) = "white" {}
Cull Off ZWrite Off ZTest Always
Mix SrcAlpha OneMinusSrcAlpha

#pragma vertex vert
Fragment fragment of #pragma

#include "UnityCG.cginc"

appdata structure
float4 vertex: POSITION;
float2 uv: TEXCOORD0;
v2f structure
float2 uv: TEXCOORD0;
float4 vertex: SV_POSITION;

float4 _NewTex_ST;
v2f vert (appdata v)
v2f o;
o.vertex = UnityObjectToClipPos (v.vertex);
float2 worldXY = mul (unity_ObjectToWorld, v.vertex) .xz;
o.uv = TRANSFORM_TEX (worldXY, _NewTex);
return or;
sampler2D _NewTex;

fix4 frag (v2f i): SV_Target
fix4 col = tex2D (_NewTex, i.uv);
come back

How to reach left Alpha sprite look? And yes, I'm totally noob in shaders.