question

The clients who buy my shirts are military members serving overseas. As of a few months ago, nobody ever had a problem getting their order shipped to their military postal address, which is technically considered to be inside the the United States. Now, for some reason, anytime anyone tries to place an order, they get notified during the checkout process that the item can't be shipped to their selected address. Amazon generally has no problem shipping other items to APO and FPO addresses. So, what has changed, and can it be fixed so that our military customers can once again order what they want?