You can also check out our excellent blog post about Old Content Auto Publish
How to auto publish old blog posts to social media from WordPress
After setting "Auto Publish Old Posts" followed the instruction, I get no log in "Logs/History" tab,
and also can't see any post in my Facebook page. Can you have me to troubleshoot this?
1. Make sure that you didn't disable WP Cron in wp-config.php file.
If you find this line in it:
define( 'DISABLE_WP_CRON', true );
you'll have to remove it if you want the Auto Publish Old Posts to function correctly.
2. Try disabling plugins such as WP Crontrol, WP-Cron Control, etc..
They might change the standard execution of WP Cron feature.