We all run into technical difficulties sometimes. Fortunately, there are a few things you can take care of yourselves.
1. Did you or your site's Content Editor approve the changes? Until they're approved, changes won't show up on live versions of the website.
2. It's possible your changes are cached. Our Drupal sites are a very large, complex system, and there are multiple caching layers to keep performance up and page load times down for our site visitors. Cached changes are pushed through every few hours, at intervals determined dynamically based on server loads. Please wait a few hours and see if your changes show up.
If your changes are very urgent, or if your changes do not appear after 6 hours, contact Digital Communications for help.
While logged in, check the Admin menu at the top of the page you want to customize. If there's a "view draft" option, click that to make more changes. It helps to remember that when there is a draft version of the page, you can customize the draft, but not the "live" version of the page.
For sub-navigation to appear, a page must have a menu link, and the page must be published. You can check both through the "edit" option in the top Admin menu, which takes you to the back end of the page. Then look at the "Menu settings" tab and the "Publishing options" tab, respectively.
Drupal generates sub-navigation lists dynamically based on your page's position in the site Menu. Until it's published, Drupal doesn't "see it" in the menu when you preview the page, so the sub-navigation block doesn't show up.
If this is a newly created page, it also must be approved by an Editor.