I'm reimplmenting a QuickTime video application using AVKit and AVPlayerView using Xcode 10 on a late 2013 MacBook Pro. The app gets a notification containing the name of the video file to open and the time to which to scroll the video display. All this happens correctly, but when I attempt to scroll the video using a two-finger trackpad gesture, the video jumps back to the start. If I reposition the video time by "replaying" the notification, (but not reopening the file itself), then the two-finger gesture now correctly scrolls the video.
Any clue to where to start looking? The same "Play" button is the firstResponder in each case.
Richard