This thread is resolved. Here is a description of the problem and solution.
Problem: What is the difference between duplicate and translate independently?
Solution: The option "Overwrite with [language] content" converts a translation to a duplicate. The way to undo such a connection between posts is by entering each post on the native WordPress post editor screen and select the open "translate independently" at the right upper corner on the sidebar (language options).
If the option "translate independently" is not available then this means that the post is not a duplicate of another post.
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