Problem: If you're experiencing issues with WooCommerce orders disappearing from the orders tab when their status is changed to 'completed' or 'being processed', and you have identified that the 'WPML Multilingual CMS' plugin is involved, we can help. Solution: We recommend the following steps: 1. Navigate to WPML > Settings. 2. Scroll to the Post Type Translation section. 3. Set the translation preference for the Order(shop_order) post type to Not Translatable and save the changes. 4. Clear the caches from your site and browser, then check again.
If this solution does not resolve your issue, or if it seems outdated or irrelevant to your case, please check related known issues at https://wpml.org/known-issues/, verify the version of the permanent fix, and confirm that you have installed the latest versions of themes and plugins. We highly recommend opening a new support ticket if you need further assistance. You can do so at WPML support forum.
