Language Switcher works, but not when logged in!

Hello, not sure why, but when I'm logged out of my Drupal site and view it as an anonymous user, the Language Switcher menu properly switches a page from one language to another. But when I'm logged into Drupal as an admin, and try to switch languages, the menu links properly switches the menu text into the second language, but not the content.

An example: Let's say node/1 is the English version of a page, and node/2 is the German version.

When logged out, the switcher correctly switches en/node/1 to de/node/2. But when logged into Drupal admin, switching from en/node/1 brings me to de/node/1.

Thanks in advance for any help!