LiteSpeed Webserver

The admin notice "Unyson: Your website is hosted using the LiteSpeed web server. Please consult this article if you have problems backing up." indicates that your web hosting company uses the LiteSpeed web server. It seems that LiteSpeed encounters issues with all WordPress scheduled tasks that extend beyond a very short duration, including backup plugins.

You need to make changes to the files .htaccess and wp-config.php located in the root folder of your website:

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 are already exist):

define('DISABLE_WP_CRON', true); 

define('ALTERNATE_WP_CRON', true);