Playing with Fire

Exact same problem. There are plants around the statue and the quest never triggers.

I've run around the statue at least a hundred times at various distances, speeds, and with all of my characters and it absolutely refuses to trigger.

I've watched videos of others doing it so I know I'm not doing anything wrong, I've got the letter from the body, I'm moving in the right direction, and I've covered every reasonable distance from the statue itself. I did notice that there are no plants around the statue in every one of the videos where I've seen the quest completed properly. I tried lowering my graphics from Ultra to very low, and every setting in between hoping the plants would go away, and they remain even at the lowest settings.

Whoever put those plants around the statue broke the quest. They need to be removed.

EDIT: Fixed. Turns out it wasn't the plants at all, it was Mantle. I switched over to DirectX and the quest suddenly worked. If it's not working for you, switch over to DirectX. If you prefer Mantle, you can switch  back once you complete the quest.

Note to devs, Mantle breaks this quest for some reason.