Where/how does WP sneak into my template here?

Hello,
I noticed a few days ago, that somehow my wordpress conjures additional <p> in my template.
E.g. is in the template

<div class="media-body">
                                    <h4 class="mt-0"><?php the_title(); ?></h4></a>
                                    <p><a href="<?php the_permalink(); ?>" style="color: #006621;"><?php the_permalink(); ?></a><br />
                                    <a href="<?php the_permalink(); ?>" style="color: #00285a;"><?php the_excerpt(); ?> [mehr...]</a></p>
                                </div>

Played out:
<div class="media-body"><a href="test"><h4 class="mt-0">Boden</h4></a><p><a href="test" style="color: #006621;">test</a><br><a href="test" style="color: #00285a;"></a></p><p><a href="test" style="color: #00285a;"><span class="excerpt_part">test</span></a></p><a href="test" style="color: #00285a;"> <span style="color:#3498db"><u>mehr</u></span> test</a><p></p></div>

Where do the opening and closing <p> come from?

I have already deactivated the plugins and in the functions.php I can not find such an entry. Does anyone here maybe have an idea?