The first time I got this quest, I was able to complete it by essentially doubling the defense rating. Today, I got this quest and successfully defended the settlement. It's defense rating was 18. I have now built it to 53 and the quest still shows as though I need to build more. There are 10 beds, 10 people, 12 food, 12 water, 16 power... I have no idea how to complete this quest. If I go "see Preston", the only other step, I know it will complete but not mark off that objective as completed. (Same problem in a different settlement yesterday...so I figured it might be something I missed...but two??)

Ideas?