Out of 10 or 12 hatchery sets, I've only had one end up pasty. It was slower shipped and in cold weather with 3 lost.
I agree that cold or stress caused it. I got them warm, and put additive in water and thoroughly cleaned. It never returned.
I know some breeds need trimming but I thought once you cleaned them up it was good to go if conditions were corrected. This may be why questions of current temps etc are coming in. Glad you ware on top of it though, I remember how tedious it was to carefully soak/wipe and repeat it was.