I've been trying to understand how spawners work here but i can't get to the top of it. Do mobs need some block type to spawn? My setup with water under the spawer doesn't seem to work and the mobs keep spawning on top of it; If i put slabs on top of the spawner the mobs don't spawn at all. Anyone has any suggestions on how i can make it work? If you want post a screenshot of what works for you. Thank you in advance.