Shulker Boxes glitched

After loading a world any Shulker Boxes that have been placed previously have lost all their contents. I've also noticed that you need to use a pickaxe to collect them, else they just break without creating a drop & using pick block on them just gives you an empty Shulker Box (even if the target was named in an anvil, the result is still a generic Shulker Box of the same colour).