Loaf changing while cooling

Thanks in advance for any advise you can give. This loaf was made with a overnight poolish then mixed, kneaded and proofed in a Zojirushi bread machine. Then shaped for a second rise and baked in a Dutch oven. If comes out smooth with a firm crisp crust. As it cools the crust softens which is fine, but the crust either cracks or wrinkles. Any ideas how to fix this?