The admin notice “Unyson: Your website is hosted using the LiteSpeed
web server. Please consult this article if you have problems backing
up.” means that your web hosting company uses the LiteSpeed webserver.
LiteSpeed appears to have problems with all WordPress scheduled tasks
that last more than a very short time – including all backup plugins.
You need to make changes to the file .htaccess and wp-config.php which are located in the root folder on your FTP server:
1) .htaccess (add this line at the bottom):
RewriteRule .* - [E=noabort:1]
2) wp-config.php (add these values or replace old ones if they exists):
define('DISABLE_WP_CRON', true);
define('ALTERNATE_WP_CRON', true);