How to fix WordPress stuck in maintenance mode
To exit from the maintenance mode, you need to remove the .maintenance file. This file can be easily removed by connecting to the backend of the website using FTP. If you are using cPanel, you may use the File manager option to remove the .maintenance file.
At times removing the .maintenance file may not fix the issue. If you find that WordPress is still stuck in maintenance mode even after removing the file as per the above method, try editing the ‘WP_INSTALLING’ part in wp-activate.php to false.
define (‘WP_INSTALLING’, false);