I've had this problem before with a different hen that was just starting to lay. this time it's my Starlight green egger and she's always laid in a nesting box but now twice she's laid outside. they have 3 clean nesting boxes inside and barely use the one in the middle so idk what to do. It's also WINTER and eggs FREEZE. I think it's because by the time she wants to lay (middle of the day) someone is already in the same box so she screams but then I guess she just lays outside. My Rooster pointed me out to the first one outside as I did not see in and he called me over to it. Also, they have a run that has hay on the ground for warmth in their feet and not cold dirt so that also may be a reason.