Spawning animals without falling through floor?

Hi there,
i know its an old topic, but i saw people can spawn animals but they wont fall down trough floors or foundations (as Build plugin do).What could that mod be?
I want to spawn animals on several floors but they keep falling down lol

Thank you.

 

entity.create assets/bundled/prefabs/autospawn/animals/bear.prefab

 

Thx, but its same thing, animals fall trough floor

 

This is probably due to a recent rust update, that stopped animals from climbing rocks and such? Now they just no clip through them rather than jump up and down.