Every UIAlertController disappear automatically before user responds - since iOS 13

I've got exactly the same problem, and fixed it by holding the window in which the alert is being presented in a strong variable.

You can hold a window for presenting alerts in you AppDelegate, for example, and use it in your UIAlertController extension.

//In app delegate
let alertWindow: UIWindow = {
    let win = UIWindow(frame: UIScreen.main.bounds)
    win.windowLevel = UIWindow.Level.alert + 1
    return win
}()

Then, in your extension:

public extension UIAlertController {
    func show() {
        let appDelegate = UIApplication.shared.delegate as! AppDelegate
        let vc = UIViewController()
        vc.view.backgroundColor = .clear
        vc.view.tintColor = Theme.mainAccentColor
        appDelegate.alertWindow.rootViewController = vc
        appDelegate.alertWindow.makeKeyAndVisible()
        vc.present(self, animated: true, completion: nil)
    }
}

---

You will also need to make sure your alert window is removed from view when your alert is dismissed, otherwise your app will become unresponsive, as all taps will be handled by the (invisible) alert window, that's still on top of everything. I do this by adding this code to the handlers of all actions in the alert:

(UIApplication.shared.delegate as! AppDelegate).alertWindow.isHidden = true

You can try this solution also. It is working form me.

write below method in your class.

func presentViewController(alertController: UIAlertController, completion: (() -> Void)? = nil) {
        if var topController = UIApplication.shared.keyWindow?.rootViewController {
            while let presentedViewController = topController.presentedViewController {
                topController = presentedViewController
            }

            DispatchQueue.main.async {
                topController.present(alertController, animated: true, completion: completion)
            }
        }
    }

Then call it from your code as below

let alertController = UIAlertController(title: "Discard Photo?",
                                                message: "Your photo will not be attached",
                                                preferredStyle: .alert)
        alertController.addAction(UIAlertAction(title: "Keep Photo", style: .default, handler: nil))
        alertController.addAction(UIAlertAction(title: "Discard", style: .default) { (_) -> Void in
            self.PhotoStack.deletePhoto(at: index)
            self.cameraBtn.isEnabled = true
        })

        self.presentViewController(alertController: alertController)