WPML: the results of a search are not displayed in the correct language. Why?

When I am on another language than the main language, the results of a search are not translated. They appear in the default language instead. How to fix that?

When you use WPML with HBook, you need to enable "Language filtering for AJAX operation". You will find this option in WPML > Languages. For more details regarding this option, please refer to WPML documentation here.