Epona
Sonic: 1 Nov 2006 - 8 Jan 2022
For fuck's sake - I can put up with pretty much every bug this game had, but bugged 'come to the aid of <X> settlement' are just a pain in the arse. Turn up to a corpse and maybe a rattle of gunfire from my effectively designed defence systems, get no confirmation of win, wander round a bit, leave to do something else. Fail mission.
I've found with those the key is to stand around and stand around a bit more, the main attack can take ages to trigger, or a second wave can take ages to trigger. (10 minutes in one case for me, which can seem like an age in a game when you're just standing around). Sometimes running around in the vicinity of the settlement can find an enemy stuck behind a tree or something.
The only time one has ever properly bugged out on me was when during the attack there was a giant radscorpion that had spawned under the ground, could see its health bar when I was facing it and all the turrets were going insane firing at the ground. Reloading from a save before I travelled there and trying again just gave me the usual raiders to kill and it worked fine.