same thing happened to me with a parmesan, that cracked after a few hours in the brine. Resouces suggested that the brine was too acidic, and it was the case, but the damage was done. Now I make my best to make sure mold does not make its way inside the cheese: i let the rind dry a age for 3 weeks, then vacuum- packed
could it be a lack of pressing? Was the bottom of your cheese elevated to let air circulate? When cheese is older, cracks can also appear when RH is too low.