I see it does not support with Alternative Layout: blog but you can try with this tweak:
+ Open templates/ja_nuevo/html/mod_articles_category/blog.php file
From
if (version_compare(JVERSION, '3.0', 'ge')){
JLoader::register('TagsHelperRoute', JPATH_BASE . '/components/com_tags/helpers/route.php');
Change to
JLoader::register('NuevoHelper',T3_TEMPLATE_PATH.'/templateHelper.php');
$moduleIntro = $params->get ('module-intro');
if (version_compare(JVERSION, '3.0', 'ge')){
JLoader::register('TagsHelperRoute', JPATH_BASE . '/components/com_tags/helpers/route.php');
and from
<div class="category-module<?php echo $moduleclass_sfx; ?> category-blog">
change to
<?php if($moduleIntro) : ?>
<div class="module-intro text-center"><?php echo $moduleIntro; ?></div>
<?php endif; ?>
<div class="category-module<?php echo $moduleclass_sfx; ?> category-blog">
Let me know if it helps