YAHMAN

ZIPANG

When you enter the HTML code directly, the layout changes depending on the p and br tags that WordPress automatically inserts.
<pre><code>remove_filter( 'the_content', 'wpautop' );
</code></pre>
It can be solved by adding the above code. 
However, this will disable all auto-inserted p and br tags. 
It is not user-friendly.
This plugin can be partially disabled.
Just enter the part you want to disable in the shortcode.
<pre><code>[jo]your HTML code[/jo]
</code></pre>
The author of this plugin loves text editors.

Just Output

WordPress automatically inserts p and br tags, but disables them in shortcodes.

Embeds for YouTube vs Just Output