Apparently, if you try to open a chest in creative mode, it will not bring up the chest interface. Instead, the chest opens and closes before your eyes. This has been confirmed on all world types, but only on creative mode. Whether this was implementef at all or not is unclear. But either way, this ruins map making.

How to reproduce:
1: Go into a creative world on any map type.
2: Place a chest down.
3: Try to open the chest.