I suspect that there is a set number of chests that can spawn at once in any given area. Loot one and another spawns somewhere else shortly after to replace it. You can see this happening for sure in small areas like delves and public dungeons. It would be hard to prove but it likely works the same way in a larger zone as well.

Old thread here, but still relevant question:

How does this work, in (say) a space like a Public Dungeon?

I'm particularly thinking of The Vile Manse, where not only is there the question of how chest spawns are determined, but the dungeon itself is cut in two: once you jump down the hole, it's literally impossible to get back up again.

If you keep racing around the upper half grabbing chests as they spawn, will you eventually get to a point where no more can spawn in the upper half because all the allowable chests in the dungeon have spawned in the lower half?

And if you then jump down to the lower half, is it possible to run out of chests *there*, and have them never respawn down below any more, because all the respawns end up being in the upper half, which you can't get back to without exiting the dungeon and going back in the front entrance?

Asking for a friend who's trying to farm the Lurker-Skin Sheath antiquity fragment...