Non-player entities teleport to Y 500+ to 32767 height when transported from the End to the Overworld

When trying to teleport a mob from the End to the Overworld, it teleports to 32767 height above the world spawn.

Steps to reproduce:

1. Move to the End.
2. Teleport any mob through the portal to the Overworld.
3. Teleport to Overworld.
4. Teleport (in the Overworld) to 32767 height above the world spawn.

Observed results:
Mobs teleporting through the portal from the End to the Overworld are teleported to 32767 height.

Expected results:
Mobs will teleport to the surface of the Overworld.

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Original Description:
I have tried to bring a shulker to the overworld by minecarting it into the portal then breaking the minecart. The result is that the minecart item is transported, but the shulker itself vanishes, he does not reapear, to my knowledge, ever again. Super frustrating bug if you are planning on making a farm.