Mine practically always do the same as yours and I do leave mine locked in the coop portion for at least a week before I let them into their run. I have an elevated grow-out coop and the first night most and usually all go to sleep in a pile near the door but on the ground. I have a run attached to that grow-out coop that is pretty predator proof. They don’t leave that area until they all start to sleep in the coop.
Every night after they have settled down, I toss the ones that are sleeping outside into the coop. They are really easy to catch after it is dark. Each brood is different. Some catch on immediately and the second night they put themselves to bed in the coop. Others may take over a week to catch on. A “normal” progression is that a very few put themselves to bed inside the coop after a night or two of doing that but others stay outside. Every night more put themselves to bed until eventually all do. Usually within a week all of them are going inside.
One of the funniest things I’ve seen happened last year with about 16 chicks. The first night they all tried to sleep outside so I tossed them in and locked them up. The next evening just as they were settling in for the night I went down there to do something else. They were all settling in outside but when they saw me they went inside the coop. It took maybe three minutes before all of them were inside. I never had a problem with any of them after that.
Then I’ve had groups where all of them stayed outside after more than a week before any started going inside on their own. It took over two weeks before they were all going inside.
Normally my brooder raised chicks start to roost on the roosts at night somewhere between 10 to 12 weeks of age. I’ve had some start by 5-1/2 weeks and some take a lot longer than 12 weeks but 10 to 12 is normal. I’ve noticed the ones that start roosting earlier ae also the ones that go into the grow-out coop easier, even if they sleep on the floor of that coop and don’t roost.
If you can lure them inside with that treats trick, which can work, and lock them inside a little before dark, that may help teach them to go to bed themselves. Being able to call them by rattling a treats bucket or using a call is really helpful in other ways too. It’s a good thing to teach your chicks, just always give them a treat when you use it.
