iOS: UINavigationController title overlaps with viewcontroller content when page is scrolled

I am using a UINavigationController to display a WkWebview page's URL as the navigationItem.title of a viewcontroller (which holds the wkwebview). The title is displayed fine, but when I try to scroll the page in my view controller (which my navigation controller wraps around), the title in the navigation controller overlaps with my page content. How can I prevent this overlap?

        self.controller.view = self.webView;
        self.controller.navigationItem.title = self.webView.URL.absoluteString;            
        self.navigationController = [[UINavigationController alloc] initWithRootViewController:self.controller];
        [self.navigationController setNavigationBarHidden:NO animated:YES];