My POV is, it is the time of year.
I think they are waiting for the days to lengthen.
If they were eating the eggs, you would still get an egg song and the crouching behaviour when you approach them. If you are getting neither of these, then its just a matter of wait and see what the Spring/longer daylight hours brings. Which could mean, February
Also, pure breeds can take longer to reach POL depending on when they are born. The pay off to this is, they live longer (thus lay for longer) than hybrids.
I only have pure breeds and I am almost *desperate* for them to lay an egg (all under one year; except one who is over 1yr but has been in moult and has not resumed laying - YET!). By that same token, I introduced 4 x 1yr old bantams to my garden last weekend and two are in regular lay!
Chickens are delicate creatures and much depends on age, breed, amount of sunlight, lack of disturbance, when they were first hatched, how well they feel in themselves, what messages they get from the rest of the flock, how receptive they are to mating, sunlight hours, feed regulation, water consumption, mites, lice, disturbance, routine, flock dynamics and a whole host of other factors.
What have I learned? I've learned they have prolific times and down times. I've learned I have to go with the flow; when eggs are in abundance, store them well to see you through the "drought" times. I have learned chickens are delicate creatures who dance to their own, biological, tune. I have learned that egg-laying isn't anything like a KFC drive thru! Just because you want it/desire it/feel you *need* it, doesn't mean it will happen at your whim and fancy. I have learned to respect the chook and their cycle of life
Just my thoughts; hope I haven't caused any offense. x