Me neither,
Followed all the tuts, tried every conceivable combination, tried scenes with tiny scales and ones 10's of Km wide! All I get is a constant fog over the whole scene, so nice atmospheric distance effect.
Something is very broken with fog in V3 I think. I have never managed to get the effect Brograph do, even following step by step. Tried using octane lights instead of octane daylight. Nothing works!
Very frustrating as I'd love to use Octane for outdoor landscapes but until we get workable haze/fog its not really possible. z-depth is a work-around but it doesn't fade away correctly like real haze does..
Using latest version on OSX by the way but I haven't seen anyone get this to work.
EDIT: I just decided to give up on the environment fog and just add a fog volume to the scene. Set the density to 0.5 and the step length to 1 and Bam! Lovely volumetric hazy fog.
I think this is the way forward. Forget the add medium button in octaneSky and just add a volume.
Word of warning: Don't make it too big to start with and untick it until you've set the voxel size pretty big or it will eat all your system RAM. Start high and slowly dial back.