Depth issues with a shader

Hi! I am using the shader below to render objects in the scene, but having depth issues with the objects even when Transparent tag is added. This is not a clipping plane issue either.

 Shader "VertexColor Transparent Specular" {
 Properties {
     _Shininess ("Shininess", Range (0.03, 1)) = 0.078125
     _SpecularColor("_SpecularColor", Color) = (1,1,1,0)
     _MainTex ("Base (RGB) Trans (A)", 2D) = "white" {}
     _GlossColor ("_GlossColor", Color) = (1,1,1,0)
 }
 SubShader { 
     Tags { "Queue"="Transparent" }
     ZWrite On
     Alphatest Greater 0
     Blend SrcAlpha OneMinusSrcAlpha
     ColorMask RGB
     LOD 250
     
 CGPROGRAM
 #pragma surface surf MobileBlinnPhong exclude_path:prepass nolightmap noforwardadd alpha
 half4 _GlossColor;
 half4 _SpecularColor;
 
 inline fixed4 LightingMobileBlinnPhong (SurfaceOutput s, fixed3 lightDir, fixed3 halfDir, fixed atten)
 {
     fixed diff = max (0, dot (s.Normal, lightDir));
     fixed nh = max (0, dot (s.Normal, halfDir));
     fixed spec = pow (nh, s.Specular*128) * _GlossColor;
     
     fixed4 c;
     c.rgb = (s.Albedo * _LightColor0.rgb * diff + _LightColor0.rgb * spec * _SpecularColor.rgb) * (atten*2);
     c.a = 0.0;
     return c;
 }
 
 sampler2D _MainTex;
 half _Shininess;
 
 struct Input {
     float2 uv_MainTex;
     float4 color : COLOR;
 };
 
 void surf (Input IN, inout SurfaceOutput o) {
     fixed4 tex = tex2D(_MainTex, IN.uv_MainTex);
     o.Albedo = tex.rgb * IN.color.rgb;
     o.Alpha = IN.color.a;
     o.Specular = _Shininess;
 }
 ENDCG
 }
 
 FallBack "Mobile/VertexLit"
 }