Well, Andy, thx again for your answer.
Exoplanet is a really great theme, I think. Now, when I work from the french backend I can define via the customizer the french links in the slider and they will actually be correct in the french frontend (and didn’t change in the german frontend, the lead language).
So, this URL information is somehow stored and produces the correct results. Missing is IMHO only the [page title] and the [excerpt] of the specific language page (of which the url is already fetched).
Exoplanet free/pro including a multilingual front page slider would really be something. Without a ml slider it’s really only good for 1 language. How can I help?