It seems, you’ve not changed post process material to “Before Transclucency”, what I mentioned in comments above.
If you’ll turn “Color Opacity” to 0 in the “Fog_Global_Color”, and check “FogGlobal_DistanceX100” parameter, you’ll achieve visible skybox too 
Also, my blueprint is designed for use with material instance, so you can change parameters in real time without compiling shader (In case you didn’t know about that). Here’s the screenshot of parameters.
