When the MySQL password contains special characters (e.g. ') and a plugin is disabled (or presumably any other action is taken that modifies config.ini.php), some special characters get escaped with \' and Matomo breaks with a Database access denied as the password isn't correct anymore.

Matomo 4.12.1

This might be a bug in https://github.com/matomo-org/component-ini instead of Matomo itself and might be related to matomo-org/plugin-LoginLdap#308