Kazuma YAGYU

This plugin changes the WordPress’s native formatting rules to keep the numbers of the line breaks you wrote. 
It adds tags as many as line breaks in posts, comments, or both, even if the line was vacant. 
You can change the settings below in the admin panel. For example: you can choose to add tags for wrapping the paragraphs or not.
<h4>Settings</h4>
You can choose settings below.
<ol>
<li>Choose the target area: in posts, comments, or both(default).</li>
<li>Choose the breaking tag format: (default) or .</li>
<li>Choose the tag which the paragraphs will be wrapped with: tag(default) or none.</li>
<li>Shortcodes that you want to exclude from tag wrapping. 
This doesn’t work if you choose “none” in option #3. 
Default is only “caption” but you can set multiple shortcodes separating “|”. Ex. “caption|map”</li>
</ol>
<h4>Attention</h4>
This plugin doesn’t work with the Visual Editor, so far.
<h4>For Japanese users</h4>
このプラグインは行末に を追加します。 
記事投稿時の改行の数だけ が追加されます。 
段落にタグを追加するか、といったいくつかの設定ができます。 
※ビジュアルリッチエディターではうまく動作しません

Vacant Line BReaker

Wordpress ignores multiple line breaks normaly. This plugin breaks lines as may as you want.

Jonathan Desrosiers

Linchpin

Aaron Ware

Note: This plugin does not support the block editor but should continue to work without issue when using it with custom post types and the <a href="https://wordpress.org/plugins/classic-editor/" rel="ugc">Classic Editor Plugin</a>.
Before WordPress displays a post’s content, the content gets passed through multiple filters to ensure that it safely appears how you enter it within the editor.
One of these filters is <a href="https://codex.wordpress.org/Function_Reference/wpautop" title="wpautop" rel="nofollow ugc">wpautop</a>, which replaces double line breaks with <code></code> tags, and single line breaks with <code> </code> tags. However, this filter sometimes causes issues when you are inputting a lot of HTML markup in the post editor.
This plugin displays a checkbox in the publish meta box of the post edit screen that disables the <a href="https://codex.wordpress.org/Function_Reference/wpautop" title="wpautop" rel="nofollow ugc">wpautop</a> filter for that post.
Also adds a ‘wpautop’, or ‘no-wpautop’ class to the post_class filter to help with CSS styling.

Toggle wpautop

Easily disable the default wpautop filter on a post by post basis.

Vacant Line BReaker vs Toggle wpautop