It seems that this achievement may be bugged for some. After I unlocked all the perks, my achievement progress bar was at 94%.
What I did to unlock it is :
- to unplug my ethernet cable (then beeing offline)
- to delete my local save (the cloud save needs to be sync before)
- to start a new game until being able to unlock perks (more or less when you open a 2nd horizon site)
- to unlock enough perk (I was at 94% before, so I needed 4-5 perks, but to be sure, I unlocked 6)
- to quit the game and remove my local save again
- to replug my ethernet cable
- to restart the game while online
when the game started to download my cloud save, the achievement popped.