Grymm
2
If you are reporting that many/all NPCs stop spawning after you build in that/any area, then that is correct - building anything will block NPC spawns to some distance around the built pieces. That has always been the case.
On private servers Admins can modify this setting, allowing NPCs to spawn closer or only further away to any builds.
But if your fault-log is that NPCs stop spawning around a build, then that is not a fault.
Maybe you need to add more details?