I have an odd bug which, while by no means game breaking, is rather annoying.
The settler I have assigned to my weapons stand in Sanctuary will not man it. He still wanders around the town. However, if I go find him, I can buy weapons and ammo from him.
This has happened with three diffferent settlers I assigned to the weapon stand. I have a general store and a clinic which are manned and working fine.
This is an odd bug, to say the least, and it is a little upsetting that I have to go find the guy anytime I want to trade.