With my Buff Orpintons I have 8 of them that have started laying... the first pullet started laying in the floor and has never layed anywhere else. The others use the nests...I keep messing up her nest in the floor and she just makes a new one for the next day lol. Last night I add a little more nesting material to the nests and put down a few pieces of plywood where she normally lays every day... maybe that will make her look elsewhere for a nest.
Good Luck!