Hello there @XD_XD2!
From what I could gather around the community, what you are encountering here is a conflicted interaction between geo collections and caches. I would suggest creating an invisible, proxy collision mesh around your cliff, and set it as a collision surface for the Niagara particles. Alternatevily, you can enable GPU Raytracing Collisions for Niagara, following the guide below:
If you need more resources related to Niagara and collisions, please check the following tutorials:
