How is your hen?
We had a Maran that we left out to free range once and shut the run/coop because we did not want our dog to get into it -- the Maran paced by the run door for hours -- in the sun, panting -- and we had no idea what was wrong with her. She ended up looking very bad, insisting on being by the run door, until finally she dropped in front of it. She was dehydrated because she would not move from the run door to water and it finally dawned on us that she was frantic because she had yet to lay that day and could not get into her nest boxes. She WOULD NOT lay anywhere else. That egg was right at the point of lay and, likely due to her dehydration, it did not move at all the rest of the day. The next day we had to do a warm soak and assist with the egg removal. Now we always watch if the hens pace once or twice and are outside of their run/coop. Each time, left to their own devices, the hen in questions high-tails it to the coop to lay.
It seems as though, once they decide on where they want to lay, come hell or high water, you are not going to change their mind. Or my hens are really stubborn!