Post process material UV bug when constraining the aspect ratio

1. Create an empty project and default level.
2. Create a new post process material that only samples from PostProcessInput0  [Image Removed]
3. Setup a post process volume in the level to use the new material
4. Launch PIE and enable Default Constrain Aspect Ratio in the PlayerCameraManager object

Note the screen will be cut off as if the UVs start from the left without skipping the back bar region.  [Image Removed]