Breadcrumbs in Drupal are basic by default. The breadcrumbs will follow the menu structure of your main navigation. If you implement a page at about-us/this-page and about us is the main navigation item, your breadcrumb will be about us / this page. If your parent page is not that about-us page in the menu, your breadcrumb won't follow the URL structure, it will follow the main navigation.
- The page has two menu items that link to it, making the breadcrumb the first menu path the system can find regardless of how you navigated to the page
- The parent menu page title is different than the actual page menu item label, so it can look wrong