iOS 11 NavigationBar back button issue

Question

I set backbarbutton in a base ViewController viewDidLoad like below:

    if (@available(iOS 11, *)) {

    UIImage *backButtonImage = [[UIImage imageNamed:@"icon_return"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
    self.navigationController.navigationBar.backIndicatorImage = backButtonImage;
    self.navigationController.navigationBar.backIndicatorTransitionMaskImage = backButtonImage;

    self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];
}

but I got a small icon, but is not in the correct position

who can give me some tips, I have spent a whole day to solve this, but can not get any idea.