Second node instance SKPhysicsBody not responding to collision - swift

Question

I've been trying to create a simple game in SK where the ball would bounce off the tops of trampolines that spawn gradually. Collisions work fine with the first trampoline but I'm having problems registering it when ball hits second trampoline spawned in run-time. Anyone might have a clue what I've been doing wrong?
Here is the code.
import SpriteKit
import GameplayKit
class GameScene: SKScene, SKPhysicsContactDelegate {
var ball: SKShapeNode?
var trampoline: SKShapeNode?
var cam: SKCameraNode?
var hasHit: Bool?
var hasCollided: Bool?
var hasMoved: Bool?
func createBall() {
ball = SKShapeNode(circleOfRadius: 50)
ball?.position = CGPoint(x: 0, y: -600)
ball?.fillColor = .red
ball?.strokeColor = .red
let ballPhysics = SKPhysicsBody(circleOfRadius: 50)
ball?.physicsBody = ballPhysics
ballPhysics.categoryBitMask = 1
ballPhysics.collisionBitMask = 0
ballPhysics.contactTestBitMask = 0
ballPhysics.affectedByGravity = false //NO GRAVITY!
ballPhysics.isDynamic = true
addChild(ball!)
}
func createTrampoline(x: CGFloat, y: CGFloat) {
let rect = CGRect(x: x, y: y, width: 100, height: 20)
trampoline = SKShapeNode(rect: rect)
trampoline?.fillColor = .blue
trampoline?.strokeColor = .blue
let trampolinePhysics = SKPhysicsBody(rectangleOf: CGSize(width: 100, height: 20))
trampoline?.physicsBody = trampolinePhysics
trampolinePhysics.categoryBitMask = 2
trampolinePhysics.collisionBitMask = 0
trampolinePhysics.contactTestBitMask = 1
trampolinePhysics.affectedByGravity = false //NO GRAVITY!
trampolinePhysics.isDynamic = true
addChild(trampoline!)
}
override func didMove(to view: SKView) {
physicsWorld.contactDelegate = self
cam = SKCameraNode()
self.camera = cam
self.backgroundColor = .darkText
hasHit = false
hasCollided = false
hasMoved = false
createBall()
createTrampoline(x: -50, y: -10)
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
for touches: AnyObject in touches {
let location = touches.location(in: self)
let move = SKAction.moveTo(x: location.x, duration: 0.1)
ball?.run(move)
}
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
if (!hasMoved!) {
let vect = CGVector(dx: 0, dy: 600)
ball?.physicsBody?.applyImpulse(vect)
ball?.physicsBody?.affectedByGravity = true
hasMoved = true
}
}
override func update(_ currentTime: TimeInterval) {
// Called before each frame is rendered
if (hasHit == true) {
cam?.position.y = (ball?.position.y)!
}
}
func didBegin(_ contact: SKPhysicsContact) {
let vect = CGVector(dx: 0, dy: 1500)
if (((contact.bodyB.node?.position.y)! - (contact.bodyA.node?.position.y)!) > 0) {
if (!hasCollided!){
hasHit = true
hasCollided = true
print("collision")
contact.bodyB.applyImpulse(vect)
createTrampoline(x: -50, y: ((ball?.position.y)! + CGFloat(3000)))
}
} else {
print("bad coll")
hasCollided = false
}
}
}
Thanks in advance.