...They just starting using the roost 5 days ago and i have 2- 4ft wide roost and this is where they go?! Should I just leave them alone or put something up there to block them from getting up there? They seem pretty happy
Yes, that is where they go. They will try to get as high as they can. That's just them being chickens. No matter how high the roost is, they'll always be on the lookout to see if they can get up higher. If you want to block it off, you can, but as @azygous said, they'll get too big to get up there soon enough. It's not a big deal.