Glass shader turn white when double sided!? Am i misunderstanding somethig???

Can someone send help?
There must be a very stupid issue cus i am a newb.
I got this glass surface shader with a normal map
when i tried to turn it double sided by adding Cull Off, the whole things turn white.
it doesn’t seem to be the problem of _Color.

Shader "Custom/Glass" {
	Properties{
		_Color("Color", Color) = (0.5, 0.5, 0.5, 1)
		_MainTex("Albedo", 2D) = "white" {}
		_Smoothy("Smoothness", Range(0,1)) = 0.5
		_Shininess("Shininess", Range(0.01, 1)) = 0.078125
		_myAlpha("Over All Alpha", Range(0.0, 1.0)) = 0.5
		_NorTex("Normal", 2D) = "bump"{}

		//Rim
		[Toggle(RIM)] _RIM("Fresnel Rim?", Float) = 0
		_RimColor("Fresnel Rim Color", Color) = (0.49,0.94,0.64,1)
		_RimAmt("Fresnel Amount", Range(0,5)) = 1.5
	}

	Subshader
	{
		Tags {"Queue" = "transparent" "RenderType" = "Transparent"}
		LOD 100
		Cull Off
		ZWrite OFF
		
		Blend SrcAlpha OneMinusSrcAlpha
		CGPROGRAM
		#pragma surface surf StandardSpecular alpha:premul
		#pragma shader_feature RIM // rim fresnel toggle
		
		sampler2D _MainTex;
		sampler2D _NorTex;
		half4 _Color;
		half _Shininess;
		half _Smoothy;
		fixed _myAlpha;

		float4 _RimColor;
		half _RimAmt;
		
		struct Input
		{
			float2 uv_MainTex;
			float3 lightDir;
			float3 worldPos; // world position
			float3 viewDir; // view direction from camera
		};

		void surf(Input IN, inout SurfaceOutputStandardSpecular o)
		{
			
			float rim = 1 - saturate(dot(IN.viewDir, o.Normal)); // calculate fresnel rim

			#if RIM
				o.Emission = _RimColor.rgb * pow(rim, _RimAmt); // fresnel rim
			#endif
			
//Output
			fixed4 c = tex2D(_MainTex, IN.uv_MainTex)* _Color; 
			c = (c-0.5)*10 + 0.5;
			o.Albedo = c.rgb;
			o.Normal = UnpackNormal(tex2D(_NorTex, IN.uv_MainTex));
			o.Smoothness = _Smoothy;
			o.Specular = _Shininess;
			o.Alpha = _myAlpha;
		}
		ENDCG
	}

		FallBack "Transparent/VertexLit"

}

@bgolus

Nevermind I figured it out

It’s the rim that’s causing the problem.