[Resuelto] Different languages in the directories - 404 with just one language others works fine

Background of the issue:
Hello, my site works and translates correctly for almost everything except that I can't see the pages for Italian > it. I always get a 404 error. I can do the Italian translations from your enlace oculto interface. The problem comes from the different languages in the directories option in WPML>LANGUAGE. Only for the /it/ sub-directory. If I create a new language, for example German, everything works even if different languages in the directories option is ON. If I pass the simple permalinks in WP and Language title added as a parameter in WPML it works for all. But it's impossible to see Italian Page, always 404 page on the /it/ subdirectory. What I've done: - Disable all plugins. - Change with 2024 theme = same problem. - Remove the language 'it' and any existing translations in ../wp-content/languages/plugins/ - Delete the wpml key of the website. - Delete the remaining MO and PO files for the removed languages. - Do a WPML reset to remove tables from the database and deactivate the plugin. - Delete and reinstall WPML plugin. - Change folder of my site reinstall wordpress with a new blank database. = Same problem: 404 on Italian pages.

Symptoms:
I always get a 404 error for Italian pages in the /it/ sub-directory. Others languages are ok.

Questions:
Why do I get a 404 error only for one language, Italian pages in the /it/ sub-directory?
How can I fix the 404 error for the Italian pages while using different languages in directories option in WPML?