Wordpress Shortcodes not working on posts (single.php) but working on pages (page.php)

Question

I'm asking for help after a day of no luck in finding the solution.

I have shortcodes inside my active plugin and they are working fine on pages but don't work on single post pages (single.php). By not working I mean completely not loading in final frontend source (no desired code and not even the shortcode snippet itself).

I'm using a fresh install of _underscores generated theme.

NOTE: I know it's the theme that's obstructing the shortcodes somehow because when I change the theme to twentyfifteen the shortcodes work.

I tried about 30 solutions (using debug on, installing what the file ... no errors, no warnings)

I would truly appreciate some help or suggestions on how to find the bug in my theme.

Here is my setup: my single.php and content.php

single.php

<?php
/**
 * The template for displaying all single posts
 *
 * @link https://developer.wordpress.org/themes/basics/template-hierarchy/#single-post
 *
 * @package MyTheme
 */

get_header(); ?>

    <div id="primary" class="content-area">
        <main id="main" class="site-main">

        <?php
        while ( have_posts() ) : the_post();

            get_template_part( 'template-parts/content', get_post_type() );

            the_post_navigation();

            // If comments are open or we have at least one comment, load up the comment template.
            if ( comments_open() || get_comments_number() ) :
                comments_template();
            endif;

        endwhile; // End of the loop.
        ?>

        </main><!-- #main -->
    </div><!-- #primary -->

<?php
get_sidebar();
get_footer();

content.php

<article id="post-<?php the_ID(); ?>" <?php post_class(); ?>>

    <header class="entry-header">

        <?php the_title( sprintf( '<h3 class="entry-title"><a href="%s" rel="bookmark">', esc_url( get_permalink() ) ), '</a></h3>' ); ?>

        <?php if ( 'post' == get_post_type() ) : ?>

        <div class="post-details">
            <div class="post-details-left">
                <i class="fa fa-user-circle"></i> <?php the_author(); ?>
                <i class="fa fa-history"></i> <time><?php the_date(); ?></time>
                <i class="fa fa-sticky-note"></i> <?php the_category(', '); ?>
                <i class="fa fa-tags"></i><?php the_tags('', ', ', ''); ?>
                <?php edit_post_link( 'Edit', '<i class="fa fa-pencil"></i>', '' ); ?>
            </div>

            <div class="post-details-right">
                <div class="post-comments-badge">
                    <a class="post-comments-badge-link" href="<?php comments_link(); ?>"><i class="fa fa-comments"></i> <?php comments_number( 0, 1, '%'); ?></a>
                </div>
            </div>

        </div>

        <?php endif; ?>
    </header>


    <?php if ( has_post_thumbnail() ) { ?>
    <div class="post-image">
        <div class="post-image-hvr">
            <?php the_post_thumbnail(); ?>
        </div>
    </div>
    <?php } ?>


    <div class="post-excerpt">
        <?php the_excerpt(); ?>
    </div>

</article>

Again, any suggestions are very welcome!

Answer 1

You're not actually outputting the page content (e.g. the_content()); just an excerpt (the_excerpt()).

Did you write the shortcode code that's having the problem? Did you add a filter for the excerpt?