There are many different reasons you could be getting fewer eggs. This time of year many chickens molt and quit laying. That way the protein and other nutrients that were going into egg procuction can now go to feather production. This is my number one suspicion in your case, but I don't know your particular situation that well.
Often, when production drops, one or more are hiding them from you, laying in a nest somewhere. This is real common.
It is possible something is eating or taking your eggs. With my egg eater, she would only eat one egg a day and often there was evidence left behind. Sometimes part of the shell and often a wet spot in the bedding. She was not shy about eating in front of me either. It turned out she would open an egg and a couple of the others would help her eat it. Once I got rid of her, the others quit. They had not yet learned to open an egg themselves.
A snake will usually eat a few and not return for a few days while it digests what it ate. The eggs totally disappear, but sometimes the snake will hang around. Not always, but sometimes.
Usually if it is rats, they leave egg shell behind. But sometimes the hens will clean up empty egg shells, so that is not a positive sign one way or another.
Possums, skunks, or raccoons will probably eat the egg right there, but they may carry it off a short ways. Usually you can find an egg shell somewhere around. A favorite place for raccoons to take it might be on top of the coop.
When all eggs start disappearing wthout a trace, I suspect the family dog. Some dogs learn that when they hear the egg sone, a treat is ready in the coop.
Then you cannot really rule out a human if the eggs disappear withut a trace.
If you can, I suggest you lock them in the coop for a whole day to see if you start getting eggs. This may mean they are hiding a nest or you may have locked out a predator. At least you will have a clue. You can also put a marked egg in the coop and see if it disappears. Again, maybe a clue.
But if you see a lot of feathers laying around, suspect a molt.
Maybe not a lot of help I realize, but it really could be many different things. Good luck!