Wow I seriously think people have forgot how to use each functions, or just don't care to look any more. ..this question is probably asked every week by some one. ..
The coral is acclimating to your tank, either because you didn't do it right or because it is a leather and this is how they do things, providing your water parameters are any where near what they should be for keeping a tank alive , the leather will be fine. .just don't move or play with it. .they need time to adjust. .they require high flow and good light and they are not overly particular about water quality. .
Again leave it alone it will be fine in a day or so