I presume that the court ordered post-secondary child support, under a law similar to RCW 26.19.090. The basically says that even though the child has reached the age of majority, the child remains a dependent of the parents. In which case, that obligation is imposed on both parents – and it does not matter where the child is living. What does matter is whether they continue to be in that dependent situation. The order is based on
Age of the child; the child's needs; the expectations of the parties
for their children when the parents were together; the child's
prospects, desires, aptitudes, abilities or disabilities; the nature
of the postsecondary education sought; and the parents' level of
education, standard of living, and current and future resources. Also
to be considered are the amount and type of support that the child
would have been afforded if the parents had stayed together
The child is required to
enroll in an accredited academic or vocational school, must be
actively pursuing a course of study commensurate with the child's
vocational goals, and must be in good academic standing
and payments are automatically suspended (not terminated) when these conditions are not met. Also, they necessarily terminate at age 23, not "when the child graduates". Other states have different laws, but "moving out" is not a violation of the order or law, unless it specifically is in the particular case.