Resolved
Reported for: WPML Multilingual CMS 4.5.1
Resolved in: WPML 4.6.8
Overview of the issue
When you choose to use a directory for your site’s default language in the WPML → Languages → Language URL format options, you will notice that if you remove the language code from the URL, you can still access the content in default language.
Workaround
We don’t have a workaround at the moment but our developers are aware of this situation.