Same problem here on a Galaxy Note. I always thought the Stylus was more a functional part of the OS, not the app. I also note (pun not intended) that it works on the menu buttons at the top – just not in the gamefield itself.
Our development team did some research and says that this is a problem with one of the third-party toolkits we use for the game. Our current thoughts are that we will probably wait for that company to fix/implement stylus support rather than trying to do it on our own. Sorry about that! We’d like for styluses to work, too.