[Geschlossen] WPML replace my content with original language

Background of the issue:
I am trying to manage translations by duplicating a page from Italian to English and manually translating it. I have removed the sync between languages. The issue can be seen on this page: versteckter Link

Symptoms:
Randomly, pages that were already translated into English revert back to Italian, including both the content and the page name.

Questions:
How can I prevent translated pages from reverting to the original language?