What happened: In a joined dungeon there was 3 chests spawned in an elbow or L shape the graphics could not decide which to use as the double. sorry I broke one before I thought to take a screenshot.

What should of Happened: the game should of checked and changed the spawn placement of the dungeon chests so they did not appear in this formation.
coords: x67 y60 z191
seed:7851170404155105626