More info is needed, there are several reasons for soft poop especially for a new chin.
How long have you had the chin? Stress can cause soft poops, and moving to a new home is stressful, so if the chin is new it could just be still settling in. It can take some chins a month to fully settle in, some more time some less.
What are you feeding it? and is it the same food it was eating before you got it? Sudden change in food can cause the chin's poop to get soft.
Have you given it any treats? Most treat sold in pet stores are not chin safe. Also chins should not have any fruits, nuts, seeds, vegetables, or any animal products (milk, cheese, bone, meat, eggs, etc).
Is the poop smelly or slimy at all? That could indicate an gut infection.