The bug

I made this system that the second I spawn a certain mob, it would teleport them right into the Void (-512 to be exact) but some of them don't teleport there. Instead, they act as if they are there, but their bodies are still where they were when I teleported them.

How to reproduce

1. Place a repeating command block with the command

   /execute as @e[type=cow] at @s run tp @s ~ -512 ~
   

2. Spawn some cows with a spawn egg
   → The cows visually don't teleport into the void