Facetime keeps reconnecting

I'm using iPad air and iPhone 6 plus, not sure if that's relevant, ever since I updated to iOS 9.0.2, my FaceTime keeps "reconnecting", I talked to the exact same person and exact location, it was perfectly working (we can talk for over hours) but now it can't even last for 3 mins. I tried to turn off/on FaceTime and restart, it doesn't work, is there anyone have the same problem? Please help!! Thanks!!