For example for the nightmare level. I want to use a base which basically a fortress. The problem while the event start, more than half of the NPCs spawn under the foundation cuz the building is too huge. Any idea where to change that? Some like spawn radius away from center point.

This is the link of the fortress im using: https://steamcommunity.com/sharedfiles/filedetails/?id=2367675962

increase the protection radius