Swift swipe gesture recogniser errors - ios

Question

I'm building a iOS Swift (Sprite kit) game. I'm using swipes to move the player. While testing I've found out that everything works just fine on most devices. However, a few devices do not recognise the swipe. Needless to say, the game doesn't work without the swipes. It's very odd that it works on almost all devices but a few.
My code is below. (Note: It's cleaned up to show only the code relevant for this case)
Edit
The app is currently being tested on actual devices. All devices run the latest iOS software. Mostly iPhone 5, a few 6 and 5S. Error occurs on iPhone 5S.
Am I missing something? If not, what else could I try?
override func didMoveToView(view: SKView) {
addSwipes()
}
func addSwipes() {
let swipeRight:UISwipeGestureRecognizer = UISwipeGestureRecognizer(target: self, action: Selector("swipedRight:"))
swipeRight.direction = .Right
view!.addGestureRecognizer(swipeRight)
let swipeLeft:UISwipeGestureRecognizer = UISwipeGestureRecognizer(target: self, action: Selector("swipedLeft:"))
swipeLeft.direction = .Left
view!.addGestureRecognizer(swipeLeft)
}
func swipedRight(sender:UISwipeGestureRecognizer) {
// Do code here
}
func swipedLeft(sender:UISwipeGestureRecognizer) {
// Do code here
}