Did you have the same problem as myself? my hens waited till I put the wheely bin down while I was doing garden work, so I didnt have to keep standing up, I put the bin on ground level. the chooks thought "Great" this will be a good egg laying place and within an hour of my break time three took advantage of it, well two weeks have gone by and they are sitting in turns, all three of them.
No didn't have that problem I ran out of nest boxes and the big pots seemed to appeal to the hens and a brick on each side to stop it rolling and some nesting material and away she went .:]