To conserve water, modern building codes require low-flow toilets in new construction homes. It is normal for these types of toilets to take more than one flush to clear the bowl.
If you are having challenges clearing the bowl, it may help to hold the handle down for the full duration of the first flush.
Under most circumstances, toilets that take more than one flush are normal and beyond the scope of a warranty. If you continue to have challenges, you most likely will need to contact a professional.