node preview term label always displays source original language label

Steps to reproduce: French term label in German preview

1. Install drupal in French
2. add Deutsch
3. enable content_translation
4. edit the article content type, enable translation
5. make sure the content type has a taxonomy term reference to tags vocabulary
6. enable translation of tags vocabulary
7. add a term such as Français, translate it to Deutsch
8. select add an article content and select the term Français
9. press the preview button
10. tags label shows up as Français
11. change the language prefix of that preview page to de (deutsch)
12. taxonomy term shows up as Français, expected Deutsch

see screenshots
Français preview

Deutsch preview