Dissmiss completion block doesn't work. Swift

I have PhotoBrowser (it inherits from UIViewController) as a presentedViewController. I present it from UITableViewController. The PhotoBrowser presents actionMainController (it inherits from UIAlertController) when I tapped on button. I want to call another UIAlertController, when I select one of the actions in the actionMainController and display the second UIAlertController immediately after its dismissed but completion block doesn't work. I want to add that dismiss the actionMainController succeeds, it works

class PhotoBrowser: SKPhotoBrowser {

    // MARK: - Controllers 

    private var actionMainController = UIAlertController()

    // MARK: - Lifecycle

    override func viewDidLoad() {
        super.viewDidLoad()
    }


    // MARK: - override var

    override var prefersStatusBarHidden: Bool {
        return true
    }

    // MARK: - functions

    func editAvatar() {
        debugPrint("removePhoto")

        actionMainController = UIAlertController(title: nil, message: nil, preferredStyle: .actionSheet)

        actionMainController.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))

        let deleteAction = UIAlertAction(title: "Delete Photo", style: .destructive) { (action) in
            self.deletePhoto()
        }
        let takePhoto = UIAlertAction(title: "Take Photo", style: .default) { (action) in

        }
        let choosePhoto = UIAlertAction(title: "Choose Photo", style: .default) { (action) in

        }
        actionMainController.addAction(deleteAction)
        actionMainController.addAction(takePhoto)
        actionMainController.addAction(choosePhoto)

        present(actionMainController, animated: true, completion: nil)
    }

    private func deletePhoto() {
        actionMainController.dismiss(animated: true) {
            // TODO: it
//            self.showDeleteActionSheet()
        }
        showDeleteActionSheet()
    }

    private func showDeleteActionSheet() {
        let deleteActionController = UIAlertController(title: nil, message: nil, preferredStyle: .actionSheet)
        deleteActionController.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
        let deleteAction = UIAlertAction(title: "Delete Photo", style: .destructive) { (action) in

        }
        deleteActionController.addAction(deleteAction)

        present(deleteActionController, animated: true, completion: nil)
    }
}

Your completion handler is not called since your alert has already been dismissed and you are again trying to dismiss the alert.

actionMainController.dismiss(animated: true) {

     self.showDeleteActionSheet()
}

Instead you should do some work on the completion handler of Action as

let deleteAction = UIAlertAction(title: "Delete Photo", style: .destructive) { (action) in

    self.showDeleteActionSheet() 
 }