In course backup and restore, activities titles are not passing multilang filters

Enable the multilang filter and set it to apply to 'Content and headings'. Install the Russian language pack (ru). Create a course. Visit the course. Turn editing on. Insert an activity, e.g. a Choice. Set title to <span lang="en" class="multilang">Title EN</span><span lang="ru" class="multilang">заглавие RU</span> Save and return to course. Cog→Backup. Click next on the appearing /backup/backup.php page. Cross check that, on the following page, the choice title does pass multilang filters and says Title EN – if you switch to Russian, заглавие RU Do the backup Restore the backup in a new course Cross check that the choice title does pass multilang filters and says Title EN – if you switch to Russian, заглавие RU