I finally managed to track down the lighting bug and traced it to the volumetric clouds. I have temporarily disabled the clouds in the main menu which will fix it until a more permanent fix is found.
Lighting Bug Fix
Source: Steam Community (opens in a new tab)
Build and release context
Steam update times within 24 hours of this post. Matching dates do not confirm which build it describes.
Build 10032364 · public branch
Steam updated · First observed