Matt Twinley
Pooping outside the litter box isn't uncommon. Around 10% of cats do this at some point in their lives.
Like humans, cats can have bathroom issues when they're ill. Diarrhea, constipation, and other health problems can be the cause
Digestive issues can make it hard for cats to control when and where they poop.
Constipation can make it hard for a cat to poop in the litter box. Dry poop is a sign of this issue.
Cats can be picky about the location of their litter box. Ensure it's in a quiet, accessible place.
Any deviation from their routine can stress cats. Consider recent changes in their environment.
Ensure the litter box is away from anything that might scare your cat.
Newly adopted cats might take time to adjust. Ensure their litter box is in a private and accessible place.