Summary in reading options not working

To rule out any theme-specific issue, try switching to the unedited default Twenty Thirteen theme for a moment using the WP dashboard.

Switching to the default twenty thirteen parent themes does not solve the problem.

I don’t have an option like that on my Dashboard; are you using a plugin that enables that behavior? I do have an option that allows me to choose between “Full text” and “Summary” for RSS feeds, though.

The option to choose between “Full text” and “Summary” is in
Settings > Reading > “For each article in a feed, show”
for me.

I have summary selected but it’s showing the full post on homepage, which I don’t want.

That setting doesn’t control how your home page is displayed, it controls how your RSS feed is displayed. To display excerpts on your home page, you can copy content.php from your parent theme to your child theme, and then change this code:

<?php if ( is_search() ) : // Only display Excerpts for Search ?>
	<div class="entry-summary">
		<?php the_excerpt(); ?>
	</div><!-- .entry-summary -->
	<?php else : ?>
	<div class="entry-content">
		<?php
			/* translators: %s: Name of current post */
			the_content( sprintf(
				__( 'Continue reading %s <span class="meta-nav">&rarr;</span>', 'twentythirteen' ),
				the_title( '<span class="screen-reader-text">', '</span>', false )
			) );

			wp_link_pages( array( 'before' => '<div class="page-links"><span class="page-links-title">' . __( 'Pages:', 'twentythirteen' ) . '</span>', 'after' => '</div>', 'link_before' => '<span>', 'link_after' => '</span>' ) );
		?>
	</div><!-- .entry-content -->
<?php endif; ?>

to just:

<div class="entry-summary">
  <?php the_excerpt(); ?>
</div><!-- .entry-summary -->

Thank you. I am trying this right now. I will update in a sec ??

Hmmm this did not fix the issue.

So I figured it out. I have to put a Alt + Shift + t where I want the summary to end in the visual editor of post editor.

Thanks