Looking closely, the roosting pole you have is way too thin for your heavy birds! I wouldn't be surprised if they roost on that much wider board that is the top of the nesting boxes. Much easier on their feet and much more sure footing. Of course that meana when they have to go, all that crap will end up in the nest boxes(which don't appear covered at all). Just a thought.
The roosting pole was put in when they were much tinier chicks - now that they're almost 4 months old I believe you're right, it's time to upgrade to big chicken roosts

And maybe the pic has some funky perspective but the nest boxes are covered
