Problem with connect my BB-8

Hi, I am using Playgrounds v1.5 on my iPad Mini 4, and I have an Sphero BB-8. If I using Sphero BB-8 App, I can connect, and control it. When I run the code in Sphero.playgroundbook which downloaded from https://developer.apple.com/swift/blog/?id=38, it connected correctly. But If I click the "Connect Robot" button in Sphero Arcade or Sphero Template, it keeping show me "Searching for Robots", and can not find or connect my BB-8. So, what can I do for play with my BB-8? Thank you.