Weird grey bar renders on disabled planar reflections

NOTE
This is best seen if you are in a mobile Preview Rendering Level

There is some rendering defect that can be seen as the camera moves around the Planar Reflection area.

You can also see some weird clear box around the head next to the planar reflection floor as well. Please see HeadPlanarReflection.gif

This happens in 4.16.2

This does not happen in PIE in 4.15.3

1. Open QAGame
2. Open TM-ShaderModels
   • Allow shaders to compile
3. Travel to the Planar Reflection Room

Result: A grey bar dynamically moves up and down the floor depending on camera's angle

Expected Results: Planar Reflections render consistently even when disabled