Hi Dave and welcome to the forum, hope you don't mind but I've moved your post to the Cheddared (Milled) Type Board.
Most people (me included) who have cheese cracking problems are due to rapid dehydration from being placed in a very low humidity environment like a household forced air type fridge. The rapid dehydration happens in the outer of the cheese causing it to shrink but the inside stays moist and does not, thus the cracks of fissures on surface. This picture in the top right of this webpage
is an extreme case when I first started making cheese.
If you could add some info (batch size, pressing weight and time and if turned, drying environment and when cracks became noticeable) it would help decipher if this the root cause of your problem. Pictures would make it easier.