View is not displayed - ios

Question

I have an alert box that takes user input and starts a download task. After the user clicks "Ok," I want the screen to show a UIView that I added an ActivityIndicator to while the download occurs. The download occurs successfully and the function correctly opens up the next controller, however, the custom view nor activity indicator are ever displayed. Here's my code:
private func getKeyFromAlert() {
let alert = UIAlertController(title: "Enter Key", message: "Enter your text key below. If you want to scan it instead, click \"Scan Key.\" ", preferredStyle: .alert)
alert.addTextField { (textField) in
let attribString = NSAttributedString(string: "Enter your app code here")
textField.attributedPlaceholder = attribString
}
let scanAction = UIAlertAction(title: "Scan Key", style: .default) { _ in
self.openSettingsForApp()
}
let okAction = UIAlertAction(title: "OK", style: .default) { _ in
let textField = alert.textFields![0]
if let text = textField.text {
let encoded = text.toBase64()
let status = APIKeychain.storeToken(encoded)
if !status {
self.displayAlertForBadKeychain(useCamera: false)
} else {
self.addLoader()
self.dismissSetup()
}
} else {
let _ = APIKeychain.storeToken("")
self.addLoader()
self.dismissSetup()
}
}
alert.addAction(scanAction)
alert.addAction(okAction)
show(alert, sender: nil)
}
The function in question that I use to display the UIView is addLoader()
The code for addLoader is:
private func addLoader() {
let frame = CGRect(x: 0, y: 0, width: view.bounds.width, height: view.bounds.height)
let loaderView = UIView(frame: frame)
loaderView.alpha = 1.0
loaderView.backgroundColor = UIColor.white
let activitySpinner: UIActivityIndicatorView = UIActivityIndicatorView(frame: loaderView.frame)
activitySpinner.center = loaderView.center
activitySpinner.hidesWhenStopped = false
activitySpinner.style = .whiteLarge
activitySpinner.startAnimating()
loaderView.addSubview(activitySpinner)
self.view.addSubview(loaderView)
self.view.layoutIfNeeded()
}
I've tried several iterations of setNeedsDisplay and setNeedsLayout without luck. I've also tried explicitly declaring this in a DispatchQueue.main.async without any affect as well.
EDIT
I added the code below for dismissSetup()
private func dismissSetup() {
let dispatchGroup = DispatchGroup()
dispatchGroup.enter()
DispatchQueue.global(qos: .background).async {
if self.updateDatabase {
//This will start the download process
let _ = WebDataFetcher(dataStack: self.dataStack)
}
dispatchGroup.leave()
}
dispatchGroup.wait()
let mainSB = UIStoryboard(name: "UserInputs", bundle: nil)
let mainVC = mainSB.instantiateViewController(withIdentifier: "userInputs")
appDelegate.window?.rootViewController = mainVC
}