Shadow-casting issues with two almost identical shaders

I'm having problems with two almost identical shaders not having the same behavior when it comes to casting shadows. As you can see in the image above, the shadow for the props, and tank body is missing on Android, where as the tank tracks are working just fine.

The only difference between the shades is the cull setting (Back and Off), otherwise these two shaders are exactly the same.

Whats going on here?

Prop and Tank Body shader

Shader "Custom/Ramp Lookup" { Properties { _Ramp ("Texture", 2D) = "white" {} }

     SubShader {
           Tags { "RenderType" = "Opaque" }
 
         Cull Back
 
         CGPROGRAM
         #pragma surface surf Ramp
 
         sampler2D _Ramp;
 
         half4 LightingRamp (SurfaceOutput s, half3 lightDir, half atten) {
             half NdotL = dot (s.Normal, lightDir);
             half diff = NdotL * 0.5 + 0.5;
                         
             diff = _LightColor0.rgb * diff * (atten * 2);
                
             half4 c;
             c.rgb = tex2D (_Ramp, float2(1-diff, s.Alpha)).rgb;
             c.a = 1;
             return c;
         }
 
         struct Input {
             float2 uv_Ramp;
         };
 
         void surf (Input IN, inout SurfaceOutput o) {
             o.Alpha = IN.uv_Ramp.y;
         }
         ENDCG
     }
     
     FallBack "Standard"
 }

Tank Track shader

Shader "Custom/Ramp Lookup (No Cull)" { Properties { _Ramp ("Texture", 2D) = "white" {} }

     SubShader {
           Tags { "RenderType" = "Opaque" }
 
         Cull Off
 
         CGPROGRAM
         #pragma surface surf Ramp
 
         sampler2D _Ramp;
 
         half4 LightingRamp (SurfaceOutput s, half3 lightDir, half atten) {
             half NdotL = dot (s.Normal, lightDir);
             half diff = NdotL * 0.5 + 0.5;
                         
             diff = _LightColor0.rgb * diff * (atten * 2);
                
             half4 c;
             c.rgb = tex2D (_Ramp, float2(1-diff, s.Alpha)).rgb;
             c.a = 1;
             return c;
         }
 
         struct Input {
             float2 uv_Ramp;
         };
 
         void surf (Input IN, inout SurfaceOutput o) {
             o.Alpha = IN.uv_Ramp.y;
         }
         ENDCG
     }
     
     FallBack "Standard"
 }