[Jack Thompson]

I think I may have found the cause to the smoke...

I'm assuming you're using Content Manager with a Custom Shader Patch? If so, go to Particle FX settings and edit the Smoke Effect settings (I don't know what the options are as I'm at work atm so can't check myself)

I stumbled across this post on Reddit earlier and it reminded me of this issue! (If you read the comments it'll give you more details)

I hope this helps; let me know if it fixes the problem!