It is not uncommon for harp strings to break. They break for all kinds of reasons. They break if you are tuning one string but plucking another and turn too far before you realize it. They break because of humidity changes in your house. They break because they are made of nylon and do a lot of stretching in their lifetime. They break if they get old enough. Sometimes they break when they are brand new.
Your harp strings are not warrantied, unless breakage is due to improper design or hardware problems. If you break a string, you may end up with a “hole” in your harp for several days or more until you can get an extra string.