Quick freezing should not crack, but it will not be preserved if it takes too long. Maybe it's been there too long. This is an organic disease, and there is no possibility of relief.

2.

When cracking, water expands with heat and contracts with cold, which can be studied by yourself.

3.

Too dry. Soak in warm water for ten minutes, and then put it in the refrigerator.

4.

Sealing and moisturizing.