Stressed Sunburst Platy?

[esl97]

So I brought home a sunburst platy a week ago. He was always shy, but now I am getting worried. He is in a tank with some neon and serpae tetras and a dalmation molly. He has spent a lot of time lying on the ground, but still swims around occasionally. He also eats normally. The serpaes chase him every once in a while, but nothing major. What can I do to bring him back to his normal self??