Well, I solved my problem. The untranslated parts were custom taxonomy parts – in this case the question categories. Seems like this is a mqtranslarte bug that prevents correct term translation during AJAX call. I fixed it using this snippet added to my theme’s functions.php
if (defined('DOING_AJAX') && DOING_AJAX) {
add_filter('wp_get_object_terms', 'dwqa_question_category_ajax_filter');
}
function dwqa_question_category_ajax_filter($terms) {
global $q_config;
foreach ($terms as $term) {
if ($term->taxonomy == 'dwqa-question_category' && isset($q_config['term_name'][$term->name][$q_config['language']])) {
$term->name = $q_config['term_name'][$term->name][$q_config['language']];
}
}
return $terms;
}