This is totally normal if you are in the northern hemisphere. Whilst chicks hatched in late winter/early spring will usually lay right through their first winter, as they approach their first adult moult the following late summer/autumn, they will stop laying for several months. It is the normal cycle for a hen. Moulting takes a lot out of them and shortening days affect them too.
Chicks hatched late spring/mid summer take longer to come into lay because they are just reaching maturity as the days are noticeably shortening.
Chickens are not machines but living creatures that are affected by the seasons, like most other animals. Eggs are technically a seasonal produce, it's just that we are so used to being able to buy them in the shops whenever we want them, that we are unaware of this fact.
My hens are just starting to come back into lay now but they have had several months off and some of them may not restart until the days become noticeably longer and it may even be spring before a few of them resume.
Commercially produced eggs are mostly from pullets/young hens that are stimulated using artificial lights to keep laying and they are culled at 18 months when they go into moult, as it is not financially viable to keep them for a few months of non production. Young pullets are raised in sequence to replace them as they are culled, so that the egg production continues undisturbed. These birds have no way of knowing what season it is, as their living conditions are regulated to make them think it is spring/summer.
Most of us hobby poultry keepers are not in it for cheap eggs. Lets face it, by the time you have bought your coop and chicks and raised them and paid feed and medication and bedding etc, there is no way we can produce eggs as cost effectively as a big producer. Many of us think of them as pets with benefits, or we keep them because we want eggs produced by happy, healthy hens. This down time is part of that. If we want them to live longer productive lives then there needs to be a recovery period after each cycle and moult and it will most likely get longer each year. The bonus is that their eggs usually become slightly larger each year when they do come back into lay.
I harvest my excess cockerels at this time of year, so whilst eggs are off the menu, chicken is on it.
I hope that puts your mind at rest that there is most likely nothing wrong with your chickens. Some people use and artificial light in the coop to disguise the shortening days, but it is too late for that now as it needs to be started in early autumn.
Hopefully like my girls, yours will start producing again soon.
Regards
Barbara