Cannot edit posts or pages after duplicating installation

I have a few WP installations for different languages in subdirectories, e.g. /en/, /fr/, /es/.

The English language installation works perfectly. I used it as a template for the other languages’ installations. By the way I changed the textbook wp_options values in the new databases too.

The other language installations work on the front-end, but when I try to edit a post/page (even with quick edit), the request never returns a result, my server eventually times out.

I can confirm that I can make changes to the database, as I have changed various settings and plugins. I have tried disabling themes and plugins, to rule out their interference.

Does anyone know how to help? ??

Thanks so much in advance!!!