Ray-traced Global Illumination doesn't seem to work properly while the fog is also enabled. The ambient lighting starts leaking through the walls.
Repro:
1) Open Spotlight tunnel demo (use APV branch of the repo)
2) Make sure both scenes are loaded: Day(active) and Spotlight_Tunnel_Main
3) Bake lighting
4) Add Ray-traced Global Illumination
In the video, I show the issue first(everything looks washed out) and then at 0.10 I show the expected result.
Issue is affecting both Performance and Quality RTGI modes