New pullets figured out nesting boxes right away but older hens...

But the older hens are not using them. I had built a new coop when I got three more chicks. Everyone was moved in at the start of November. The three older hens had nit been laying for a while so the stress of the move didn't matter. The new chicks started laying at the start of December and they figured out the nesting boxes immediately. I had fake eggs and golf balls in there. Well the older hens started laying again finally after many months off. The problem is they won't use the nesting boxes! One is laying on the poop board and one is laying just about everywhere else including outside in the middle of the run. Not sure what else I can do other than hope they give in and use the new boxes. Any thoughts?