GeckoLib models invisible when added by world gen

I have a custom animated grass block that I made in blockbench for a new dimension. The block works great when placed manually or with a procedure, but it is invisible when when placed as part of world gen. The block is there, but nothing I can do can make it visible. I have tried block updates, reloading the resource pack, and reloading the world. I also tried to use a dummy block first that would replace itself when added to the world, but that does not trigger for blocks that are added on world gen. I could probably replace the grass with a static model, but that won't help all of the plants I have made that I want to add.