Not uncommon for new layers to drop eggs randomly until they figure out what's going on. After that, they tend to follow the examples of others and lay eggs in the boxes - but which boxes on what days is almost completely random. It does not sound, however, like yours are new layers.
When that happens - particularly if its consistent, I'd start inspecting the house and boxes for changes in the environment that might make one or more nesting boxes "unsuitable" - either a bird that started perching in a nest box (dirtying it up), a lack of nesting material (or a big stick in same), water or wind intrusion into one of the boxes, or some pest/predator that made them feel unsafe, or even a damaged perch (forcing them to find other accommodations).
Are there any other indications of unusual behaviors in your birds, such as avoiding the hen house?
From my own example, I recently integrated six SLWs into my flock. Birds integrated well after the new pecking order was established and things were fine - but now that they are laying too, with the lengthening days, I have a problem. In addition to the usual egg on the ground till they get their bearings, I am finding eggs in nests near perches, and even eggs on the roof of my hen house! Its been cold (for me, not them), very windy (for everyone), and wet. My hen house isn't big enough for the flock anymore (and I have to replace a perch, besides) and its showing in where they lay their eggs.
Not an issue during the day - they free range and even the run is about 900 sq ft, or even most evenings when they can stay outside the hen house, but cool (34 degrees), wet, and windy (18 mph, gusts to 25+), suddenly I have issues.
They didn't see eggs in the box so they got confused
They definitely follow the example of the older girls. The last 2 days they were back in the box
