davidR-15

Problem:
The client had two issues: First, they were unsure if using

after linking posts as translations with

should also set the thumbnail for all translations. Second, they encountered unreliability with

, where strings registered in the default language were not translating correctly.

Solution:
For the first issue, we explained that WPML provides an option to duplicate media for translations, which can be forced in WPML > Settings > Media Translation by clicking "Start". The hook wpml_apply_save_attachment_actions is responsible for media synchronization.

Regarding the difference between

and

, the former is used for string packages found at WPML > Packages, which help translate custom database tables, while the latter is for individual strings. For option strings, the hook wpml_unfiltered_admin_string is available.

For the second issue, we clarified that media synchronization options in WPML > Settings > Media Translation only affect new content. Existing content requires manual synchronization using the "Start" button. We also provided information on how WPML uses custom database tables to manage language connections and media entries, as detailed in the documentation WPML custom tables.

If the solution provided here is not relevant to your case, or if it's outdated, we highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have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 you still need assistance, please open a new support ticket in our support forum.