Changing the view mode to Shader Complexity while in Android ES 3.1 preview render will show a black and grey checkerboard in the viewport.
This does not happen in UE 4.27
Actual Result: Black and grey checkerboard when Shader Complexity is enabled
Expected Result : Viewport shows the level with color showing the Shader Complexity.
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-151566 in the post.