So I’m trying to do the Elusive Faerie Cache treasure in Ardenweald. You can see it shaded in darkness at its spawn point and requires you to pick up a lantern to the north in order to loot it. However, after I pick up the lantern and return to the spot, the treasure has phased out.
For what it’s worth, there is a world quest active in that location today. I had the same problem with another treasure yesterday where a world quest was active that we can’t see because it’s tied to campaign.
EDIT: World quest has expired from this area but the cache still will not appear.