Even the grave marker itself appears to be spectral... take a look at this video

Approaching the Grave

Note that the gravestone is clearly in the scene as I approach. Once I get within 'x' distance, it vanishes. This is the first object I have ever seen in-game that disappears as I approach it. Not sure if this is a bug, so if not I will move this elsewhere once we find a solution heh.

The spawn name is "sign_grave_of_holly_windstalker_0", and when I /goto it, it is right where it should be. Not underground or nothin. I am baffled.

Weird. I have not done those Antonica quests in quite a while so I can't remember if that happened for me (that's why I'm excited to write those quests!). I don't understand what the purpose of the grave disappearing would be?

Well in typical JA fashion, the very second I write a post, I think I figure something out.

Is it possible that the grave marker itself could physically be a part of the zone vpk, but since there is no spawn_object for it, as you approach it vanishes? I have 2 records for that "sign_grave_of_holly_windstalker_0" but neither have a model of a gravestone - just that generic 49 for signs I think.

Possible, it could be that the widget that you should have spawned is not. If it was spawned and that happened I would say that the location_id was wrong.