When a WitherSkull gets teleported above ~256 it disapears

How to reproduce:

1. Summon a WitherSkull

   /summon WitherSkull ~ ~ ~ {direction:[0.0,0.0,0.0]}
   

2. Testfor the WitherSkull to make sure it is still there (This should output something like "Found ...")

   /testfor @e[type=WitherSkull]
   

3. Teleport it 270 blocks up

   /tp @e[type=WitherSkull] ~ ~270 ~
   

4. Test again for the WitherSkull

Now you shouldn't be able to find it

Fireballs could also be affected. This may be intended because Minecraft wants to redruce lag and infinitely flying WitherSkulls will probably create lag