Makes Sense. The hens he’s had success with are the same ones that squat when I look at them funny. The ones chasing him off are actually the two lowest in the pecking order of my hens. If he tries to get on a pullet they’ll actually knock him off then go after the pullet.
That is typical pecking order behavior. The older hens are in effect protecting their prerogatives earned as the highest ranking hens in the flock. Very often a situation develops where a couple of cockerels or even adult roosters will pull a rival off of a hen before the hen and rooster can finish the sex act. This will often result in infertile eggs.