Which chest piece for the Human Specialty Armor?

Hi, I bought all the pieces of the cultural Tier 1 set for human (named "Scout"): all the skins have been unlocked and added to the achievement's progress but the chest. It's unlocked, I can use it as skin from the Wardrobe, but it didn't count for the achievement Human Specialty Armor.

I sent a ticket, but no one replied after 1 month. Anyone knows which chest piece I must buy to get this progress done?

Is it possible you got the chestpiece from a guaranteed unlock? The achievement actually predates the wardrobe system. If you notice it's not a collection, it actually requires that you soulbind the armor to a character, not just unlock it in the wardrobe. If you get a piece unlocked through an instant armor or guaranteed wardrobe unlock, it'll be available in the wardrobe, but won't count towards the achievement.

Try buying the chestpiece of a different armor class (Heavy or light). It's soulbound on acquire, so it should progress the achievement, even if you can't equip it.

I bought all the pieces with badges of honor, and usually you unlock the achievement the moment you buy them, no need to equip it. I didn't want to waste other badges of honor, but I'll try a different weight, ty.

EDIT: I bought the heavy set (always with the thief) and this time it worked (the first time was the medium version). Good enough, luckily it's just the Tier 1, quite cheap :)

The other possibility is you got the chest piece from the end of the level 20 story chapter. I'm not quite sure why but that has the same problem - it unlocks it in the wardrobe but doesn't count towards the achievement.