winnings.com

at our website winnins.com we use the plugin and found it’s really valuable and useful to meet our needs. Recently bumped the same issue and added a quick fix to the plugin.
The reason of losing meta tags when saving with quick edit is quite simple just take a look at the function hook_save_post()
it assigns the meta values from the $POST variable but quick edit form doesn’t have any fields with meta values.
Here’s how we fixed and proven to be a working solution:
find this part in the function function hook_save_post($post_id)

foreach($this->field_names as $field => $field_label) {
    //Get field data
    $field_id = "qtrans_meta_{$field}_{$lang}";
    $field_data = trim(str_replace('"', '', $_POST[$field_id]));
    $meta[$field][$lang] = $field_data;
} //end of iterating over field names

and add a condition to check if there’s $_POST data for the fields:

foreach($this->field_names as $field => $field_label) {
    //Get field data
    $field_id = "qtrans_meta_{$field}_{$lang}";
    if (isset($_POST[$field_id])) { // fix to avoid losing metadata with quick edit
        $field_data = trim(str_replace('"', "'", $_POST[$field_id]));
        $meta[$field][$lang] = $field_data;
    }
} //end of iterating over field names

I hope it helps 🙂