problem child

noun2

1. •
   Someone or something persistently difficult or vexing; a frequent source of trouble or annoyance.

   • [A]n ambitious supersonic carrier fighter called the F3H Demon . . . proved too heavy for its Navy-specified Westinghouse engine (in itself a problem child), and turned into a $265 million fiasco. — 1959
2. •
   (euphemistic) A child who is particularly difficult to raise or educate, especially due to a lack of self-control and disruptive and antisocial behavior.

   • Hill was a problem child who was sent to Woodlands because his parents couldn't handle him at home. — 2006