Top bar button disappear

[kuzevanoff]

After switch centerviewcontroller from leftViewController (didSelectedRowAtIndexPath method) with this code:

      ViewController *vc = [mainStoryboard instantiateViewControllerWithIdentifier:@"CenterViewController"];
                if (vc)
                    [appDelegate.drawerController setCenterViewController:vc withCloseAnimation:YES completion:nil];


                break;

There are no more top bar buttons (button to open/close sidebar)

Why?

Thanks