Multiverse no snow golems

Hi, I use the Winter Snow Plugin, but there are everywhere these snow golems. So I tried using Multiverse and added with /mv modify add snow_golem animals the snow golems to the excempions list. This works and they disappear but later they spawm again. And it doesnt matter if I remove or add the to the list, they despawn and spawn again after a while with both commands. I dont really know whats going on here.