Why do Breadcrumbs in Drupal sometimes display unexpected menu paths and labels?

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.

Common confusion:

• 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