Zeppelin trophy "Blimp Buster"

[Lord Fluffball]

So I completed everything in the Zeppelin mission and even got all trophies, except this one, even though I should get it as soon as I have all other Zeppelin trophies, right?

Does anybody know how to fix this?

[Radagast]

I have the same problem. I finished every other achievement and it's bothering me that a bug is preventing my 100% completion of the game.