While helping to supply Sanctuary with necessities I had some issues with the defenses request from Sturges.

I initially built 2 of the flamethrower traps and wired them each to a different power generator so that they would be "active" and they even had a little flame animation. I believe I got an update that my Defenses for the 5-person settlement was at 80%, so I continued building. I put down a Tesla trap and hook it up to one of the same generators (going for a one of each type per generator deal) and I get the 100% completion update after putting down 2 Tesla traps and hooking them each up.. but when I go try to speak to Sturges all I can do is trade supplies with him. :/ At this point I also notice that the Defense status at the top of the Workshop task bar (or whatever you want to call it) is still red and says 0, as if I haven't done anything, even though I got the quest update recognizing that I had satisfied the Defense stat completely.. but then Sturges himself wouldn't recognize it in dialogue.

I eventually got everything to update (Defense stat and Sturges dialogue) correctly after building 2 turrets. Each time I built a turret the (100%) quest update came up on the screen. Since it eventually worked, I figure it's not a big deal.. but the quest and Defense stat still didn't operate quite right at first.

I have an issue with this same quest. I finally finished this quest after having to place and re-place defensive elements as well and it popped up saying completed, but now Sturges just keeps telling me thanks and that there's nothing else he needs and that Preston wants to talk to me. However if I go to Preston he basically just says something quick that's unrelated and then walks off, no dialogue options.