Hello there and welcome to BYC!
A few things could be going on....first, check your nest boxes. If they are dirty, dusty, old bedding, have bugs, predators have been seen in the coop during the day, etc...this will scare the birds outside to lay somewhere else. So make sure they are fluffed and clean at all times.
Next, if they are out free ranging and are out really far, they may not want to come back to lay in the coop. So keep fake eggs in your nest boxes and you might keep them confined in the coop and run for the first half of the day so they have to lay in the boxes and not out in the fields.
Good luck with your flock and welcome to ours!