[تم الحل] Language Setting Does Not Work

Background of the issue:
I am trying to set up language settings on my website الرابط المخفي using WPML. Under Language URL Format, I have selected the option for different languages in directories. URL Rewrite is already enabled on the server, and we are hosting many other websites on the same server with the same settings.

Symptoms:
The language setting does not work when I try to change the language of the page. It works when I change the URL format to 'Language name added as a parameter', but I don't want that.

Questions:
Why does the language setting not work with different languages in directories?
What can I do to make the language setting work with different languages in directories?