You may need to post a picture to be certain, but cracks are usually from cheeses drying out too much or too quickly. If the curd wasn't fully knit from the pressing, the drying out can cause shallow cracks all over the surface of the cheese, or make the cracks more dramatic. Or, a moist cheese with an excessively drying rind can cause deep, wide cracks. The dry rind will want to contract, while the moist cheese inside will stay "springy".
If you're using a regular fridge, that would be the culprit. They are notorious for overdrying cheese. A solution would be to wax, or use a ripening box.