If he seems otherwise well, I would guess at time of year. In my experience they tend to go quieter and if you have more than one cockerel you find there is less competition between them as autumn arrives. Not the best time for babes I guess so the hens slow down or stop laying and the cockerels are aware of this and conserve their energy.
All starts again in the spring and the cockerels have little "arguments" to find out the pecking order for the new year.
Cockerels also seem aware of when a pullet is about to come into lay and don't tread her until a few days before you get her first egg.