The dog didn’t bark at night before and now it barks suddenly because it may be used to it. Generally, dogs will bark and look for people when they first arrive in a new environment and are not accustomed to it. However, it will get better after a week or so of adapting, so there is no need to If you are too worried, just spend more time with your dog.
Tip:
Puppies are more likely to bark, so it is best to let the puppy sleep in the owner's house. This can prevent the puppy from barking and disturbing the rest of the family.