I ended up having to manually detect the language, here’s how I solved it:
<?php if (ICL_LANGUAGE_CODE == 'fr')
{
// display the menu en francais
wp_nav_menu( array( 'menu' => 'Navigation principale', 'theme_location' => 'primary', 'container_class' => 'menu-header', 'menu_id' => 'menu-primary-navigation' ) );
}
else {
// show them the menu in English
wp_nav_menu( array( 'menu' => 'Primary Navigation', 'theme_location' => 'primary', 'container_class' => 'menu-header', 'menu_id' => 'menu-primary-navigation' ) );
}; ?>