You misunderstand me, I've produced 4 boxes of cigars, but the progress bar stopped at 2/6.
I've then tried to produce kegs of beer. The very first one I produced raised the progress bar to 3/6. The next one raised it to 4/6. Then the progress bar didn't go up any more, no matter how many kegs of beer I produced (I did 5 in total).
So I figured the text of the quest is wrong and I actually have to produce 2 of each. However running the 8h job of the chemical plant didn't raise the progress bar at all.
So now I'm stuck at 4/6 no matter what I produce!
I've create a ticket in-game as well.