A couple of thoughts... One consideration would be the access to the coop - is it easy to get in? I see pictures sometimes of small coop-over-the-run set-ups which have a very steep walk down to the run, which might be ok for going down but a little challenging for going up. Also, why is the coop lighted? I wonder if that confuses them... I know chickens WILL go into a lighted coop when it's an established behavior, but at this time of year it's not necessary to light it, and their instinctive drive to go in at dusk may be circumvented a little by having unnatural light while they're establishing a routine. If they like some particular treat, you can teach them to come for that when you call, and then use that to call them into the coop with treats in the evening. That's what I've done with new flocks in the past, seems to work. It sure would be a pain to have to put them in there every night, you want to get them self-sufficient asap, but unless you have a fortress, leaving them out is pretty risky and may establish a pattern you don't want.
