The IRS just says you "may" qualify. They don't know all your facts.
Your child qualifies if they are a "qualifying child" dependent. To be a qualifying child dependent, your child must live "at home" more than half the year and not provide more than half their own support.
Children in college are generally considered to live "at home" for purposes of the dependent rule because college is considered a temporary absence, especially if the child lives in your home there over summers and other breaks. A child in college also usually does not provide more than half their own support.
For a child in a service academy, they would not be qualifying dependents because they are not temporarily away from home and they do provide more than half their own support. The exception would be the first year. If the child reports on or after July 1, then they lived "at home" more than half the year (January 1-June 30). And probably, the support you provided at home (value of free housing, food, utilities, car, clothing, any other expenses) would be more than half their total support for the year if it was all added up.
