[Gelöst] Google indexing issue with wpml on translated pages

Background of the issue:
I am trying to index my German pages using WPML. Here is the link to a page where the issue can be seen: versteckter Link

Symptoms:
I expected to see my pages on Google, but instead, the pages will not appear on Google.

Questions:
Why are my German pages not appearing on Google?
How can I resolve the indexing issue with WPML?