I am trying to debug failing publication of scheduled posts. On a completely new wordpress installation, (using the default docker image), scheduled posts fail to get published when the correct time passes. I have enabled full php errors logging, and I have followed the steps that wp_cron takes (logging at each step). I see that in the function spawn_cron() , it arrives at the end, where it tells it to do wp_remote_post (passing the url https://mysite/wp-cron.php?doing_wp_cron=A_TIMESTAMP_HERE ) . This does not return an error, but a (serialised here for easier logging) result:

a:5:{s:7:"headers";a:0:{}s:4:"body";s:0:"";s:8:"response";a:2:{s:4:"code";b:0;s:7:"message";b:0;}s:7:"cookies";a:0:{}s:13:"http_response";N;}

I have added logging to the wp-cron.php, but it never gets triggered. Any idea what could be causing the wp_remote_post not to actually trigger the wp-cron.php ?