Step to recreate:

Step 1: Create a very large world (Over 150MB, a multiplayer SMP world can work).

Step 2: Make a shulker-box full of items.

Step 3: Occasionally, player can not place down the shulker-box but can place down NBT-block (Ender-chest, chest, etc). 

Observed result:

Shulker-box can not be place down by player (haven't checked for dispenser yet, I will update this if this bug occur again)

Expected result:

Shulker box should be placed

Update: When this bug occurs, it also prevents player from throwing the shulker-box away and using the firework rockets