iOS 11.3和iOS 11.4中的画中画问题

Question

尝试在PiP模式下的播放器中将当前的AVPlayerItem替换为另一个AVPlayerItem。我在iOS 11.3和iOS 11.4版本中遇到问题。每当使用新视频实例化新播放器项目并尝试播放时，都会删除播放器。它的奇怪行为。有人遇到过类似的问题吗？

采取的方法： 1.创建一个包含视频网址列表的表格视图 2.创建一个AVPlayerViewController（）实例 3.在tableView（_ tableView：UITableView，didSelectRowAt indexPath：IndexPath）中尝试用新的视频URL替换AVPlayerItem。

附加代码以获取更多信息

        func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
                let videoURL = NSURL(string: self.videosListArray[indexPath.row])

                if playerViewController.player != nil {
                    playerViewController.player!.replaceCurrentItem(with: AVPlayerItem (url: videoURL! as URL))
                } else {
                  let player = AVPlayer(url: videoURL! as URL)
                    playerViewController.player = player
                    self.present(playerViewController, animated: true){
                        self.playerViewController.delegate = self
                        self.playerViewController.player!.play()
                    }
                }
            }
    //Below implementation is for making the user to select other videos from tableview. 
    func playerViewControllerWillStartPictureInPicture(_ playerViewController: AVPlayerViewController) {
            playerViewController.allowsPictureInPicturePlayback = true
            playerViewController.player!.play()
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
                playerViewController.dismiss(animated: true, completion: nil)

            }
        }


    func playerViewController(_ playerViewController: AVPlayerViewController, restoreUserInterfaceForPictureInPictureStopWithCompletionHandler completionHandler: @escaping (Bool) -> Void) {
        let currentViewController = navigationController?.visibleViewController
        if currentViewController != playerViewController {
            if let topViewController =
                navigationController?.topViewController {

                topViewController.present(playerViewController,
                                          animated: false, completion: {()
                                            completionHandler(true)
                })
            }
        }
}