Well, the topic subject is pretty clear. I synthetized all seven ultimate weapons (even Dogi's and Geis'), but the achievement didn't unlock. Is this a known issue, or I just had extremely bad luck? Any way to fix it?

EDIT: It just unlocked an hour ago... I didn't do anything, I swear. Now that I check it, it seems Galaxy is having some problems tracking my progress; my time played is a couple of hours lower than it should be.