WordPress Footnotes Block Not Translatable

Overview of the issue

If you try to translate the content inside a Footnotes block of the WordPress Block Editor, you will experience that it is not available in the Advanced Translation Editor (ATE).

Workaround

• Go to WPML > Settings > Custom XML Configuration page.
• Add the following code:

  <wpml-config>
    <custom-fields>
      <custom-field action="translate" encoding="json">footnotes</custom-field>
    </custom-fields>
  </wpml-config>
  

• Add a small modification to your page in order to refresh the translation job.