Earlier today I was looting Devil's Castle on the far north of the map (Coords: 068039) and as I was moving upstairs in the main tower, I could see the loot floating in the air. The loot was few centimeters under the ceiling so I suppose it was meant to be placed on top of the ceiling/floor.

Unfortunately I don't have any screenshots of this issue but I suppose it's easy for a dev to teleport to the coords and check it out, should be an easy fix.