Chickens do sometimes sleep in nests. That doesn’t mean it should be considered normal. Poopy eggs should not be considered normal.
There are different reasons chickens might sleep in a nest. Usually it’s a design flaw though sometimes behaviors come into play. As a general rule chickens like to sleep in the highest place available so your roosts need to be clearly higher than anything else. How much is clearly higher? It depends on your coop and how it’s laid out. I like to use a foot but I have a large coop with lots of room and some separation between nests and roosts. In smaller cops less will probably work. I don’t know how yours is set up inside that doghouse.
Chickens are social animals and often like to sleep together. I don’t know how much length they have on that roost inside. They need enough length to sleep (which isn’t much) but also room to get up there and enough room to get down in the morning. If the inside of that doghouse is cluttered they may not have enough clear room to get up and down. From your photo it looks like you don’t have Silkies. Since Silkies can’t fly they are often roost challenged. Also how close to the roof are your roosts? They can crowd into a fairly small spot but they do need some room just to get up. That doghouse may be height challenged.
Since they are all sleeping together you don’t have this problem but I’ll mention it since it is so common a reason some of your chickens might sleep in the nests. Some chickens can be real brutes on the roosts. They sometimes go out of their way to attack other chickens as they are settling in for the night. It’s pretty common when I’m integrating immature chickens that they leave the roosts and find a safer place to sleep.
What material is your roost inside the coop made from and what size is it? Wood is normally the best choice for material for many different reasons. It needs to be fairly stiff so you don’t get a lot of bending. You called it a swing. How firmly is it fixed? Chickens have fairly long toes. While some people insist that a roost needs to be very wide and flat, many of us use tree branches or 2x4’s with the narrow side up very successfully. Because of the length of their toes I suggest the roost should be at least 1-1/2” wide so they can comfortably grip it. Wider is not a problem.
Chickens can be creatures of habit. Occasionally when they transition from sleeping on the floor to sleeping on the roosts they use the nests as a transition spot and get stuck there just from habit.
How much light do you have around there at night? Chickens need some dark down time. They may prefer the nest just because it is darker. This may be why they are not sleeping in the perch in the run.
So what can you do? It depends on what the problem is and it may be a combination of problems. First make sure the roosts are clearly higher than the nests and suitable for access, support, and size. Make your roosts desirable.
You want the nest open when they first start to lay, otherwise you could be training them to lay somewhere other than your nest. They are creatures of habit, you may be creating another problems by trying to solve this one. It’s a dilemma. You can block the nests off and try to get them in the habit of sleeping somewhere else, that’s a common solution. You may need to be out there pretty early each morning to open those nests back up. Still, it’s a potential solution.
You can try going out there every night after they have gone to bed and move them to the roosts. If it is dark enough so they can’t easily find their way back to the nests they should get the message fairly quickly. It doesn’t always work but it is another normal solution.
Since you are planning on some changes can you raise the doghouse and lower the nest? That would give you clear separation. Or tear out that nest and build one somewhere else, maybe external to the dog house.
It is s problem but at least you have discovered it before you get poopy eggs so you have a chance to fix it. Good luck!
