Hi,
What you’re seeing is normal with the current free version.
Automatic Translator works with one original/source language for the page. So if your site language is English, choosing English restores the original page instead of translating the current post into English.
That means if some posts are written directly in French on an English site, the plugin can still treat those pages as English-first, so English is not available as a translation target for those posts.
Right now, the free version works best when the site content has one consistent source language. On mixed-language sites, this kind of behavior can happen.
For now, the best workaround is to keep each post in the site’s main language, or create a separate English version for posts that were originally written in French.
We’re also working on a more advanced multilingual setup for a future premium version, which will handle cases like this much better.