Bug: achievement for Fang of Mokêlé

Hello,

On my ranger lvl 80 (female sylvari in Divinity Reach, around 6:30ish pm CET Friday 22), logged in, unlocked soulbeast, the achievement for Fang of Mokêlé unlocked because I got the dagger, and it had the Soulbeast Cache item marked as completed. I haven't even started PoF quest nor completed any map, that cache didn't appear on inventory, only got as completed item in the achievement.I thought it was some random display error for launch and didn't mind it, but today checking achievements the item it's still there like if I did unlock it.