I have that problem now and again. You're supposed to go into their coop at night and remove each one from the nest area and place them on their roost. You may have to do this each night until you see them do it on their own. Mine were a little stubborn, (spoiled) and they still sometimes sleep in the nest box, but I scoop their poop out every morning and keep things clean and tidy for them. So, yes they're kinda spoiled - in a way, sorta, sometimes, kinda like, you know.
When mine were smaller they would roost in the nest boxes. I finally had to cover the nests and then they all headed for the high roosts. Tomorrow they will be 15 weeks. Next week I will uncover the nest boxes, add grass and golf balls and then the wait for eggs to arrive.