Okay, so this is an odd one.
Whenever I leave Sanctuary Hills, my stats fall and my settler's happiness falls fast. The two things that keep dropping is Defense and Beds. When I'm in Sanctuary Hills, my Defense is 114 and Beds is 24. But when I'm not there, Defense drops to 5 and Beds drops to 15 (there are 19 people there, so this makes them unhappy).
I can't get my settlement happiness above 77 because of this, and if I stay gone for the length of a mission their happiness gets down in the low 60s. Also, no matter how high I get my defense -- up to 120 before -- there's always an exclaimation point next to it like its too low.
Any way to fix all this?