Continuing the issue on https://wordpress.org/support/topic/not-able-to-export-database/ , it has been found out that there are hosts with customized dB hostname settings.
Prime Mover uses PDO connections to database via MySQL-PHP library. This has been updated to support different hostname connection cases.
The following are all tested working cases for database host names which is defined in wp-config.php:
define('DB_HOST', 'localhost');
define('DB_HOST', 'localhost:/var/run/mysqld/mysqld.sock');
define('DB_HOST', '127.0.0.1:/var/run/mysqld/mysqld.sock');
define('DB_HOST', 'localhost:/var/run/mysqld/custom-mysql.sock');
define('DB_HOST', '127.0.0.1:/var/run/mysqld/custom-mysql.sock');
define('DB_HOST', 'localhost:3306');
define('DB_HOST', '127.0.0.1');
define('DB_HOST', '127.0.0.1:3306');We hope that covers pretty much everything as those syntax are also supported by WordPress when setting up DB host.
If your website uses a different DB_host setting other than above and Prime Mover cannot export database (you will see connection refused error).
Please create a bug ticket and we will cover that case.