The default behavior of WPML is to show WooCommerce reviews in the currently active language only. For example, imagine that a website has two languages:
- Language A
- Language B
If the website is viewed in Language B, WPML will automatically filter reviews and show reviews only in Language B. WPML will hide reviews in Language A because it is not the language in which a visitor views the website.
This is a standard feature of WPML plugin. It was designed to work this way.
How to Customize WPML to Show Reviews in All Languages
This WPML feature is often discussed on their support forums. Most of the topics on the forums are about showing comments in all languages. This is because WordPress is much more popular than WooCommerce. However, WooCommerce reviews are based on the standard WordPress comments, so topics and solutions about viewing all comments also apply to reviews.
Here is a link to one of the topics from the WPML support forum about this issue: https://wpml.org/forums/topic/show-comments-in-all-languages-for-each-translated-page/. If you would like to switch off filtering of reviews (comments) in WPML and show reviews in ALL languages, try implementing one of the solutions from WPML support forum (see the link above) or try adding the following code snippet to your functions.php file (please make a full backup of your website before doing it):
remove_filter( 'comments_clauses', array( $sitepress, 'comments_clauses' ), 10, 2 );
This code snippet was taken from WPML support forum here: https://wpml.org/forums/topic/show-comments-in-all-languages-3/. We cannot guarantee that this code snippet will work on your website. If it doesn't work, please reach out to WPML support for further assistance.