Hey @Saluke_5!
Both meshes (the two meshes that are gonna overlap / hit each other) should have the Generate Overlap Events
property enabled for the overlaps to count, and similarly the Simulation Generates Hit Events
property for the hit events.
The ground might not be generating hit events.
If the both meshes do indeed generate overlap events but it still doesn’t get triggered, your collision sphere’s bounds might not be exceeding the bounds of its parent mesh.
Hope these help