Did she have access to oyster shell previously?
Ever notice any coughing, sneezing, runny nose or watery eyes?
What do you feed, including treats? I would give her some poultry vitamins for a few days in a row and 1/2 tablet of calcium for 3-5 days.
It may be just a laying glitch, is she young? She may also have something else going on with her reproductive systems, but hopefully it will straighten out with calcium, vitamins and making sure she's hydrated and eating.
Not sure if moving to a nesting box is a good sign or not. I've had them move before, just seemed like they were more comfortable, but it did not solve the problem.