Archer Class Level 60 Achivement Bug.

Last night I have reached level 70 and to my surprise it seems that I am not the first Player on the Archer class to reach lvl 70 even tho nobody I asked knows of another archer player which could be lvl 70 yet. While checking my achievements I have noticed that the Level 60 achievement called Master Archer was not unlocked for me, maybe there is an issue with the Archer class in general. But perhaps I just am not the first Archer to reach 70 and the player who got the first lvl 70 achievement already has quit the game before I have started playing