Just give him time to settle in. Impaction can be caused from many things not just sand, so it would be in my books hard to blame a beardie having it purely from sand. The common reason people avoid it is because dragons are always getting sand in there digestion when kept on it, weather from eating things covered in sand or running around licking it. In saying that though in the wild they don't have fresh news paper so I guess personal opinion. This such as over feeding or feeding pray to large cause impaction and mealies are not a good choice as food as there shells over time are known for causing impaction, so if you do feed them make sure they don't take up more than 10% of there diet and try to avoid using large mealies.
Allana