I'll get this one out of the way first. The top cause for chickens to not lay is the molt. Anything is possible with chickens but I don't think so with yours.
A very common reason for you to think they are not laying is that they are hiding a nest on you. I don't know how you manage them or how likely that is but several people have been surprised by finding a nest full of eggs where they didn't think they could possibly hide one.
Something can be getting them. Most critters that eat eggs leave a sign behind, even if it is the chickens. You find either pieces of egg shell or a damp spot. In North Carolina the critters that take eggs without leaving any traces are snakes, canines, or humans. A snake eats the eggs and then disappears for a few days while it digests them. Since it is every day it's not a snake. A fox or coyote would probably be more interested in the chickens than the eggs so it's not them. A dog will sometimes leave the chickens alone but enjoy the eggs. Does a dog have access? A human doesn't always mean a stranger or a thief, some people think doing something like this is a great practical joke.
Even with a bright red comb it's possible they are not laying yet. I had three hens that waited 9 months before the first started laying, then two of them did a couple of days apart. That was early December when the days were very short. You just never know when they will actually lay. Their daughters started laying at around 5 to 6 months so it wasn't purely heredity. The breeder I got those hatching eggs form didn't understand that either.
So what can you do? I don't know how you are housing and managing them. If they free range can you lock them in the coop or coop and run for a few days to see if eggs start showing up? That would mean they are hiding a nest or you locked something out that was getting the eggs.
You can mark a real egg and leave it down there. If it disappears something is getting them.
You can look at their vents. If the vents are large, soft, and moist they are laying or within a few days of laying. If the vents are tight and dry they are not laying. Once you see the difference it's pretty obvious.
What I consider most likely is that they are either hiding a nest from you or just haven't started yet.
Technically 26 weeks but a good point.