UIView.animate not setting image and label alphas on VC change - ios

Question

EDIT: I figured out I need to resume the layer if its paused, but am not sure how to resume the layer when the view returns. viewDidLoad doesn't seem to trigger on segue
I have an app with an animation, sound, and a webView. The animation is triggered by a button and a segue to the webView is triggered by another button. If the animation is playing when the app segues to the webView, once the app segues back, I have it set so the animation restarts when the play button is tapped. This works fine
However, when the animation is paused and the view changes, upon returning to the main view, the image alpha and label alpha doesn't appear to animate... although the debugger says the alpha is changing appropriately, nothing appears on screen.
How can I get it to animate appropriately when play is tapped after returning from the WebView?
Here's the play button:
touch += 1
//define animated layers
imgLayer = firstImg.layer
labelLayer = firstLbl.layer
if touch == 1 {
print("touch = \(touch)")
self.firstImg.alpha = 0
self.firstLbl.text = ""
animateStart()
player.play()
self.playOut.setBackgroundImage(UIImage(named: "pause.png"), for: UIControlState.normal)
} else {
touch = 2
}
//toggle pause
if touch == 2 {
print("touch = \(touch)")
pause = !pause
if pause {
animatePause()
player.pause()
} else {
animateResume()
player.play()
}
}
}
and the animate start block:
func animateStart() {
print("animation started")
UIView.animate(withDuration: 4, animations: {
self.firstImg.alpha = 1
print("firstImg alpha = \(self.firstImg.alpha)")
self.firstImg.image = UIImage(named:"peter.JPG")
self.view.layoutIfNeeded()
}, completion: { finished in
if finished {
self.animateSecond()
}
})
}
and here's how I dismiss the VC on segue
func dismissVC() {
touch = 0
self.playOut.setBackgroundImage(UIImage(named: "playbtn.png"), for: UIControlState.normal)
player.stop()
initAudio()
self.dismiss(animated: true, completion: nil)
}