Guild Wars 2

hello me and my friend decided to try to gain all the achievements in the story journal. now im the leader of the party (if this is the problem) but it so happen that when we would complete something ill get the achiev.. now i’ve thought it was because i was hosting the instance but i let my friend do the same and the problem still consist. if anyone know how to help that would be greatly appreciated.,

Has he done the story and unlocked the achievements on that character? If not then that’s probably why he didn’t get them.