phyllos

a picture of the cracks for reference

Hi everyone! I really need some help, recently I’ve been having issues with my mug bodies cracking while they dry. The clay I use is PF700 and I purchase it from bath potters. I hand build my mugs and cover them up in plastic fully for around 3 days when they are done. After 3 days, I remove part of the plastic so that it can begin to dry slowly and i have had multiple mugs crack in the body, when this has never been an issue before. Is there any advice anyone can give me?