Light inside Volumetric Fog is offset in the right eye when viewing in VR with Forward Shading and Instanced Stereo Enabled
If just Forward Shading or Instanced Stereo is enabled, this does not occur.
Documentation does not cite this as a known issue
https://docs.unrealengine.com/en-US/Engine/Rendering/LightingAndShadows/VolumetricFog
Example Project attached
1. Create a project with High Density Volumetric fog
2. Add a Spot/Point light with high intensity
3. Enable Forward Shading and Instanced Stereo in Project Rendering Settings
4. Play in VR Preview
5. Observe that light is in wrong position in right eye
Oculus Rift used
There's no existing public thread on this issue, so head over to Questions & Answers just mention UE-58981 in the post.