Ambient Occlusion does not function with Forward Rendering enabled

Ambient Occlusion does not seem to function when enabling Forward Rendering. I tested the level without Forward Shading and could notice a visible difference in the shadows when Ambient Occlusion was enabled and when it was disabled. With Forward Rendering enabled there was no visible difference.

Tested in //UE4/Release-4.25 @ CL 14469661 and Ambient Occlusion does work with Forward Shading so marking as a Regression.

1. In any project enable Forward Rendering 
2. Restart the Editor
3. Navigate to Edit > Project Settings
4. Search for Ambient Occlusion
5. Toggle it on and off while observing the lighting in the level

RESULT:

Ambient Occlusion has no effect on the lighting or shadows in the level

EXPECTED:

Ambient Occlusion would function when Forward Rendering is enabled