timoT-13

Problem:
You are using DIVI, WooCommerce, WPML, and Add Ons Ultimate on your site. You need to edit 'post type settings' in WPML settings due to a message indicating that synchronization preferences for custom posts like Product Add-Ons, Groups, and Fields have not been set. These fields are associated with Add Ons Ultimate and are marked as 'not translatable'. Whenever you make changes in the WPML settings or even just press the 'save' button without making changes, all products disappear from the front end in all languages.

Solution:
We logged into your site and found that the post type add ons were set as not translatable. The group title, description, etc fields were also set as not translatable. These all need to be set as translatable or copy once. We also located the documentation here. Have you followed these steps: https://pluginrepublic.com/documentation/edit-global-groups-as-post-types/? Their documentation seems to indicate that manual translation is the correct way to translate the add on fields. We tested that on the staging site and can confirm that if you translate the product add ons manually, they show up on the frontend.
We tried using the WPML custom configuration to force the add on fields to show in the translation editor, but it didn't work. We would ask the Product Add On plugin author to provide the correct wpml-config.xml file so that we can copy and paste that into WPML -> Settings -> Custom XML Configuration. If they can't do that, let us know and we can see if we can figure out a way to get the fields into the translation editor.

Please note that this solution might be irrelevant, either because it’s outdated or not your case. We highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins. If the issue persists, please open a new support ticket at https://wpml.org/forums/forum/english-support/.