acoustic plume
If it is locked that means you haven't unlocked it, by doing whatever the achievement needs you to do...
Like if it says "Finish a race in Top 3 position" then that's what you have to do to get it to switch from a lock to the actual picture and award you the points.
slate gazelle
If it is locked that means you haven't unlocked it, by doing whatever the achiev...
i'm doing the achievement, but even after completing it's still having the locked symbol
acoustic plume
sometimes achievements take awhile to actually regsiter. also some achievements are just bugged.
Take a look on some forums or a site like TotalAchievements for the specific achivement to see if there are any issues with it
slate gazelle
it's literally every achievement i try to do