Guild Wars 2

I obtained the Asura T1 and T3 Skins via purchasing them from the gloryvendor prepatch and used them on my gear postpatch. But the achievement “The Emperor’s New Wardrobe” is still at 0/90 pieces.
Does i have to buy them again in PvE to complete this or is this considered a bug?

I got a total of 12 pieces (Ex-PvP-Skin-Version)

You must purchase the gear in PvE, pre- or post-patch in order to obtain the Achievement.