"shortcode unautop" is necessary for block-element-generating shortcodes

[szepeviktor]

https://github.com/szepeviktor/wordpress-plugin-construction/blob/master/mu-shortcode-unautop/shortcode-unautop.php

[szepeviktor]

It may be mentioned in the readme.
This is the original mu-plugin:
https://core.trac.wordpress.org/attachment/ticket/14050/plugin.php