RIR Chicken Laying Question

[TexasSam]

Searching can be futile....lock em up.
Free range birds sometimes need to be 'trained'(or re-trained) to lay in the coop nests, especially new layers. Leaving them locked in the coop for a week or so can help 'home' them to lay in the coop nests. Fake eggs/golf balls in the nests can help 'show' them were to lay. They can be confined to coop and maybe run 24/7 for a few days to a week, provided you have adequate space and ventilation, or confine them at least until mid to late afternoon. You help them create a new habit and they will usually stick with it. ..at least for a good while, then repeat as necessary.

At this point I would have to agree with @aart you should lock them in a coop/run to see what is wrong. Whether it be hidden eggs confused chickens or a diet issue.