Damian postgame quest Reward

I've beaten the Elite 4 rematch and all postgame questlines that I know of, and gotten to the point where I can talk to Damian & Nora for their legendaries.

Talking to Damian he gives me Shaymin just fine, and while he talks about giving me the first form of his starter, I don't actually receive anything and the conversation just continues on as if he had, stopping me from getting the mon.