I'm not sure if this is an intended behavior, but for some reason the move tutor doesn't work on Dragonite. The Dragonite was breeded in Generation 1, so I'm not sure what the issue is. It'd be great if this could be fixed with the Generation 3 update.
Hello Voquix, Usually if a move relearner/tutor does not work on one server, it is advised that you try another less populated server. If you see a move tutor that doesn't work it mostly just means that the server needs a restart. I hope this helps! If you have any other questions feel free to message me on discord or on the forums!