Unity Linear Fog on Mobile

Hi all :-) Have tried just about everything I can think of to get
Unity's default linear fog (or exp) to work in my scenes on the Oculus GO.

Some
people say that it works, others that it doesn't. Any clues on what I could be
doing wrong or have missed - an export setting perhaps or maybe something not added to the
camera/cameras?

Forward rendering camera, perspective, single pass.

Any help greatly appreciated :-)

EDIT: RESOLVED

Turned out to be an additive issue in that if scenes are loaded additively and the original scene didn't have fog enabled then the new scene's fog settings aren't applied cause it's assumed you don't want them. :-)