Faction Camp Issue - NPC just doesn't move/work on expanding base

so i’ve been tinkering around with Faction camp system (which i discovered few weeks ago, not gonna lie all this time playing CDDA and never know about this faction camp system)
all things worked out really good until i started expanding my base…

i managed to expand my bases by making farm, storage building and canteen but the problem is the NPC doesn’t move or work at building the farm, canteen or storage building. they just stays around the main area (Evac Shelter). leaving the farm, canteen and storage building basically “not exist at all”

is it a bug?