I've created at the bottom of a post a typical author box where I show author's avatar, name and description. It's showing the information correctly but if I change the post author to a different one, it keeps showing the old/original one information.

This is my markup so far:

<div class="author-details_info">
    <h2 class="author_info_title"><?php the_author_meta('display_name'); ?></h2>
    <p class="author_info_desc"><?php the_author_meta('user_description'); ?></p>
    <p class="author_info_mail"><a href="mailto:<?php the_author_meta( 'user_email'); ?>"><?php the_author_meta( 'user_email'); ?></a></p>
</div>

I'm wondering if someone could help me fixing that. Thanks in advance!