Render Texture only creating texture of background on android Unity 5.6.0f3

I am attempting to make a screenshot feature that allows the user to take a screenshot and share it to social media. The function works fine in editor however on android it is only creating an image that consists entirely out of the background colour

Here is my current code:

 void LateUpdate() {
         if (takeHiResShot) {
             RenderTexture rt = new RenderTexture(Screen.width, Screen.height, 24);
             Camera.main.targetTexture = rt;
             Texture2D screenShot = new Texture2D(Screen.width, Screen.height, TextureFormat.RGB24, false);
             Camera.main.Render();
             RenderTexture.active = rt;
             screenShot.ReadPixels(new Rect(0, 0, Screen.width, Screen.height), 0, 0);
             Camera.main.targetTexture = null;
             RenderTexture.active = null; // JC: added to avoid errors
             Destroy(rt);
             byte[] bytes = screenShot.EncodeToPNG();
             /*Texture2D screenShot = new Texture2D(Screen.width, Screen.height);
             screenShot.ReadPixels(new Rect(0, 0, Screen.width, Screen.height), 0, 0);
             screenShot.Apply();
             byte[] bytes = screenShot.EncodeToPNG();*/
 #if UNITY_EDITOR
             string filename = Path.Combine(Application.persistentDataPath, "Pixel8_"+System.DateTime.Now.ToString("yyyy-MM-dd-HH-mm-ss")+".png");
             System.IO.File.WriteAllBytes(filename, bytes);
             Debug.Log(string.Format("Took screenshot to: {0}", filename));
 #else
             NativeToolkit.FacebookUploadImage (screenShot, OnScreenShotUploaded);
 #endif
             takeHiResShot = false;
         }
     }

This is the output in Editor which is what I expect: But this is the output on android:

I'm not sure whats causing the difference in behaviour between Editor and Build so any help would be greatly appreciated.