Nav Mesh only affects meshes with collision below it. It’s a set of instructions over an area, and not something you can stick something to. So if you’re loading your bots (or anything else, for that matter) in an area with no collision below them, they’ll fall. Have you tried placing bots in level to be loaded, so they don’t exist until level is loaded? If you need them to exit that load area, you can instead try only loading them (in persistent level) once sub-level is loaded. Would either of those solutions work for your project?