No Shadows on Tessellated Terrain

Hi all! Long time reader, first time poster. I'm not overly familiar with Shaderlab and I'm having some trouble with a tessellated object not casting or receiving any shadows. Here's the shader:

 Shader "Terrain"{
     Properties {
            _EdgeLength ("Edge length", Range(2,50)) = 15
         _Color ("Color", Color) = (1,1,1,1)
         _MainTex ("Albedo (RGB)", 2D) = "white" {}
         _HillAlbedo ("HillAlbedo (RGB)", 2D) = "white" {}
         _Glossiness ("Smoothness", Range(0,1)) = 0.5
         _Metallic ("Metallic", Range(0,1)) = 0.0
         _NormalMap ("Normalmap", 2D) = "bump" {}
         _Height ("Height", 2D) = "black"{}
         _Tess ("Tessellation", Range(1,32)) = 4
         _Displacement ("Displacement", Range(0, 10.0)) = 0.3
     }
     SubShader {
         Tags { "RenderType"="Opaque" }
         LOD 200
        
         CGPROGRAM
         #pragma surface surf Standard fullforwardshadows vertex:disp tessellate:tessEdge
         #pragma target 5.0
         #include "Tessellation.cginc"
  
         struct appdata {
         float4 vertex : POSITION;
         float4 tangent : TANGENT;
         float3 normal : NORMAL;
         float2 texcoord : TEXCOORD0;
         float2 texcoord1 : TEXCOORD1;
         float2 texcoord2 : TEXCOORD2;
         };
         
         struct v2f {
          float4 pos : SV_POSITION;
         float3 wNormal : COLOR0;
         };
  
         float _EdgeLength;
         float _Tess;
         
         float4 tessEdge (appdata v0, appdata v1, appdata v2)
         {
             return UnityEdgeLengthBasedTess (v0.vertex, v1.vertex, v2.vertex, _EdgeLength);
         }
         
         sampler2D _Height;
         float _Displacement;
 
         void disp (inout appdata v)
         {
             float d = tex2Dlod(_Height, float4(v.texcoord.xy,0,0)).r * _Displacement;
             v.vertex.xyz += v.normal * d;
         }
  
         sampler2D _MainTex;
         sampler2D _HillAlbedo;
         sampler2D _NormalMap;
  
         struct Input {
             float2 uv_MainTex;
             float3 worldNormal; INTERNAL_DATA
         };
  
         half _Glossiness;
         half _Metallic;
         fixed4 _Color;
  
         void surf (Input IN, inout SurfaceOutputStandard o) {
             // Albedo comes from a texture tinted by color
             fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
             o.Normal = UnpackNormal(tex2D(_NormalMap, IN.uv_MainTex));
             fixed4 hillC = tex2D (_HillAlbedo, IN.uv_MainTex) * _Color;
             o.Albedo = lerp(c.rgb, hillC.rgb, (1.0 - dot(WorldNormalVector (IN, o.Normal), float3(0.0, 1.0, 0.0))));
             // Metallic and smoothness come from slider variables
             o.Metallic = _Metallic;
             o.Smoothness = _Glossiness;
             o.Alpha = c.a;
         }
         ENDCG
     }
     FallBack "Diffuse"
 }

It's worth noting that the HillAlbedo is also never being displayed anywhere, which leads me to believe that the worldnormal isn't getting updated by tesselation. Does this mean I need a second pass for the second texture and shadows, or am I just way off the mark here?

Thanks for your time.