2 months cut before roughing out, the wood has still got plenty of moisture in it, and will check on the back if left uncoated.
Coat the back with white glue, so all the moisture leaves through the belly. Now that you are roughing the staves out they will dry quickly, even with a sealed back.
I've had freshly cut hickory start to check on an exposed back, that was left uncoated over my lunch break. It was a windy day, with little moisture in the air.