Sometimes a molt isn't very obvious. In addition, when the heat hit I noticed a significant decrease in egg production. I have one hen doing poorly right now and off lay, so I"m down to 4 laying hens and I have gotten 6 eggs in the last 3 days. It has been in the upper 90s and very humid here.
As long as they are eating and drinking well, you might give some extra protein to encourage egg production and it would also help them with feather growth if they are finishing up a molt. Mealworms, cat food, tuna fish, etc. are all good sources of protein.