I'm sadly missing the final quest in the achievement window for several accounts; it was never offered after logging in 1-2 times per day. Sort of a poor experience. To top it off, the prize is another tetra box, which is extremely unexciting!
I usually only log in once a day. A couple times I logged in for other things but logging in numerous times a day or whenever it showed "next quest rotation in X hours" did not seem to matter. Many times I was given the same quest I had just done. And once or twice it was offered while I was still working on the other one. After I finished it then I went ahead and did it again anyway. I re did some of them 3 times. Finally I did get the last quest. Just make sure you keep doing any of the others related to this /ach even if they already counted, or if you had done them over and over.
I did get all in a row on my accounts. So when I had finished the first one, then I got the second one to start and so on. Until I got the achievement.
