Treasure Coffers Spawn Above Ground

Hello. I've noticed that when treasure coffers generate over water for the following levequest:

Levequest: What Peistes Crave
Level: 10
Location: Western Thanalan
Quest Giver: Totonowa

The coffers quite literally generate on the surface of the water, not submerged. They are sort of floating there. I've witnessed a number of times for this quest (serial re-roller). Unfortunately, I don't have a screenshot, but if you run the quest a number of times, the issue is easy to spot.

I also noticed (one time) in another Levequest that the treasure coffer actually spawned floating above the ground in the center of a grape vine. Details below:

Levequest: Far from the Vine
Level: 5
Location: Lower La Noscea
Quest Giver: Wyrkholsk

My guess is that this is likely not a bug, but rather done by design. I.e. perhaps there is logic to ensure that when the coffers spawn at random, they can be "seen" easily. Not sure... but I figured I'd report it just in case.

Steps:
- Initiate above levequests.
- Make note of the locations that the treasure coffers spawn in.
- Observe if they are "above" the water or ground (Far from Vine).
- Determine if this is just the way the game engine works or not.

Thanks!