Wardrobe Cultural Armour Unlock
Cultural, or any other armor (except those from a progression line used in recipes) will only be unlocked if they are still in your possession. If you have destroyed, deleted, transmuted several times, etc. said armor, it will not be unlocked.
They should be unlocked if achievement credit has been gained, just like how having one piece of a gem store set unlocked the full set, even if not having the full set in our possession anymore.
Why? If that were the case, then every armor and weapon any character had ever touched would be unlocked. Not much fun in that. Sorry to hear you didn’t keep your previous armors, but it can be a new goal, if you so desire.