Shader works in editor but not in Android - Pass 'meta' has no vertex shader

For my mobile game, I am using this general shader to replace Unity’s standard and Mobile/Diffuse shader (credits):

Shader "Mobile/DiffuseX"
        _MainTex ("Base (RGB)", 2D) = "white" {}

        Tags { "RenderType"="Opaque" }
        LOD 150
        #pragma surface surf Lambert noforwardadd

        sampler2D _MainTex;
        fixed4 _Color;

        struct Input
            float2 uv_MainTex;

        void surf (Input IN, inout SurfaceOutput o)
            fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
            o.Albedo = c.rgb;
            //o.Alpha = c.a;
    Fallback "Mobile/VertexLit"

It’s working perfectly fine in the Editor (when build platform is set to Android). However, when running on Android, I get the following error:

Unsupported: 'Mobile/DiffuseX' - Pass 'Meta' has no vertex shader

I have done a lot of research about this, but I can’t find any solutions. I have tried the following things:

  1. Adding the shader to “Always Included Shaders”
  2. Disabling shader support for “Depth Normals” and “Motion Vectors” under “Built-in Shader Settings”
  3. Turning off “Auto Graphics API” and using just OpenGLES 2.
  4. Commenting “o.Alpha = c.a”

Nothing works. Is this a bug within Unity or an error on my part? Any thoughts about a fix/workaround?

Dev environment: Unity 2018.3.0f2, Windows 10, Android build

Testing phone: Moto G5 Plus, OpenGL ES 3.2, Adreno 506, Android 8.1.0

I have the same problem, it stopped crashing after I disabled the “casting shadows” in the directional light. I’m not sure if this is the best solution…