End Portals send entities into a "null" world, causing entity loss and invalid entities

[HexedHero]

When an entity goes into a linked END_PORTAL, it'll be sent into a null world, not the correct linked world. Nether portals work fine.
[12:23:56 WARN]: DROPPED_ITEM going to: Location{world=null,x=0.5,y=100.0,z=0.5,pitch=0.0,yaw=0.0}
[12:31:56 WARN]: LLAMA going to: Location{world=null,x=0.5,y=100.0,z=0.5,pitch=0.0,yaw=0.0}