Settlers ignore/won't use doors and stairs?

[Crenickator]

So, basically, I was trying to mod in a fews walls and things for the settlement builder. Just messing with the vanilla files myself. But it seems even just duplicating the stock Guard Tower leaves settlers unable to use the stairs. They walk around to the front and stick there. Same with doors. Even just duplicating the vanilla Door Cap leaves settles unable to walk through the doorway. I'm obviously missing a step.

 

What gives?

 

Thanks.

 

EDIT: It's not duplicating the Navmeshes, is it? I assumed it would.

Edited November 27, 2017 by Crenickator