Opaque material assigned to a Material Billboard attached to a Pawn renders differently against the Sky/Infinity when moving

This is a regression. Tested in //UE4/Release-4.27 CL18319896

Opaque material assigned to a Material Billboard attached to a Pawn renders differently against the Sky/Infinity when moving. Tested against different GIs with the same result.

1. Create a Third Person template project
2. Open BP_ThirdPersonCharacter
   1. Add a Material Billboard component then set its X location to 100
   2. Add a Sprite Element in the the Material Billboard's details
   3. Expand the element and set the Material to 'M_SimpleOpaque'
   4. Compile, save, and close the blueprint
3. Play in Editor
4. Position the Billboard so that it is between the camera and the character with the sky behind the character(see gif)
5. Walk toward the camera; away from the sky

Expected Results:
The Material Billboard remains visible.

Actual Results:
Where ever the Material Billboard overlaps the sky/infinity it becomes complete see through, and remains solid against everything else.