Labels translation and Pathauto

Hi,
I have a problem with field labels that are not translated after Pathauto is enabled...

Here is what I do:
1. installing D8.
2. enabling translation modules.
3. add a second language (like French).
4. add a Language switcher block.
5. in Article content type, add a translation for the Body field label (ex. in French "Corps"), set this field translatable, and display label inline or above (hidden by default).
6. create a content in English.
7. add a translation to this content.
8. check that the content is displayed in English, then in French, according to the language selected. Result: the content AND the label are well translated according to the selected language: "Body" is displayed as the field label when English is selected, "Corps" is displayed as the field label when French is selected.
9. now install and enable Pathauto.
10. test again. Fail: the label is always in English, whatever the language selected. The content of the field itself is well translated, but not the label.
11. disable Pathauto.
12. test again. Working again.

I noticed more incoherences with languages selection, but this one is the most evident. I hope I am right with this investigation... In real is what I did: installing D8 few months ago when it was beta, updating until today, setting up a clean/empty database to do this test.

Hope it helps.