If you’re a non techie, then it’s unlikely that you disabled wp-cron (which is triggered every time someone views a WordPress page and runs background processes such as publishing a scheduled post when it’s time). On the other hand, disabling it is only a matter of adding a line to the config file, so you should check your config.php for the following:
define('DISABLE_WP_CRON', true);
If it’s there, you can try commenting it out by putting a # character at the start of the line. Then with config.php saved in your installation, look at a couple of posts, and then go to the XML Sitemaps admin page and see if it’s made the pings.
If this is indeed where the problem is, then you need to decide whether to leave wp-cron enabled or solve the problem some other way, of which I can suggest 2: run wp-cron periodically, or ping Google and Bing yourself.
Each of these can be done with a crontab command or by simply loading a URL yourself.
The ping URLs are:
https://www.google.com/webmasters/sitemaps/ping?sitemap=http%3A%2F%2Fwww.domain.org%2Fsitemap.xml
https://www.bing.com/webmaster/ping.aspx?siteMap=http%3A%2F%2Fwww.domain.org%2Fsitemap.xml
The URL to run wp-cron is:
https://www.domain.org/wp-cron.php?doing_wp_cron
Realizing that the pinging seemed to require wp-cron solved the problem for our site, but if your wp-cron is not disabled, I’m afraid the problem must be elsewhere.
