Hi @dimalifragis,
Thanks for writing in with this observation.
WP Super Cache automatically adds a couple of constants to your wp-config.php
file to allow it to manage your cache before WordPress has been fully loaded. It also cleans up after itself by removing those constants when you deactivate the plugin.
When updating your wp-config.php
file, Super Cache is very careful never to leave your config file in a half-written state, so if something goes wrong it will not break your site.
It updates your wp-config file by creating a copy with the necessary changes, then it renames the file to switch you to the updated configuration. In doing this, it appears to have modified your file permissions.
I have filed an issue for us to investigate a fix for this in a future release of WP Super Cache here: https://github.com/Automattic/jetpack/issues/27324