PHP function only returns date on some posts

I am using the following code in my wordpress page:

<article>
<?php if ( have_posts() ) : while ( have_posts() ) : the_post();?>
<section>
<h1><?php the_title(); ?></h1>
<p>Uppladdat <?php echo the_date('I M Y');?> <?php echo get_post_time('H:i:s'); ?></p>
<p><?php the_content(); ?></p>
</section>
<?php endwhile; endif;?>
</article>

And on the first blog post, it shows the date and time it's posted. On the second post, it shows only the time. On the third one, it shows date and time again.

What is happening here?

source https://stackoverflow.com/questions/71355716/php-function-only-returns-date-on-some-posts