PostProcess OnRenderImage Depth doesn't work on Android

Hi guys,

I take 2 days on this feature and I need some help
I try to create a 2 colors fog on Android : first step => get the depth buffer in my shader.

It's working well on Editor but not on my Android Device (Pixel 2).
I am on Unity 2019.2

Here is the script I add to my Camera :

Code (CSharp):

1. using UnityEngine;
2. using System.Collections;
3.  
4. [ExecuteInEditMode]
5. [RequireComponent(typeof(Camera))]
6. public class PostProcess : MonoBehaviour
7. {
8.     private Material material;
9.  
10.     // Creates a private material used to the effect
11.     void Awake()
12.     {
13.         material = new Material(Shader.Find("Kcm/Depth"));
14.  
15.         // On active le depth
16.         GetComponent<Camera>().depthTextureMode = GetComponent<Camera>().depthTextureMode | DepthTextureMode.Depth;
17.     }
18.  
19.     // Postprocess the image
20.     void OnRenderImage(RenderTexture source, RenderTexture destination)
21.     {
22.         Graphics.Blit(source, destination, material);
23.     }
24. }

Then the associated Shader :

Code (CSharp):

1. Shader "Kcm/Depth"
2. {
3.     SubShader
4.     {
5.         Pass
6.         {
7.             CGPROGRAM
8.             #pragma vertex vert_img
9.             #pragma fragment frag
10.  
11.             #include "UnityCG.cginc"
12.  
13.             uniform sampler2D _CameraDepthTexture;
14.  
15.             float4 frag(v2f_img i) : COLOR
16.             {
17.                 float depht = tex2D(_CameraDepthTexture, i.uv).r;
18.                 return depht * 38.0;
19.             }
20.             ENDCG
21.         }
22.     }
23. }

The result is perfect on editor but doesn't show anything on Android!

If you want to test, it's easy :
Create a new 3D project on Unity
Add the script on camera then play