Every time a new post copy is created
Let’s assume that you have crossposted “Hello world” post to “Site 2” and then you would like to make some changes in that post. But every time you hit “Update” button a new post copy is created on “Site 2”.
There are multiple reasons why it could happen. Let’s talk about each of them.
1. WP_DEBUG is not properly configured
One of the reasons why this could happen is that your Site 2 (where post copies are being created) returns something wrong in its REST API response body, usually PHP Warnings.
So, please open wp-config.php file on Site 2 and set WP_DEBUG constant to false:
define( 'WP_DEBUG', false );Or better use a debug.log file for your PHP Warnings and errors.
define( 'WP_DEBUG', true );
define( 'WP_DEBUG_LOG', true );
define( 'WP_DEBUG_DISPLAY', false );Of course, it would be a great idea just to fix all these PHP warnings, but sometimes it is not possible. Because even some popular plugins like ACF are full of them.
2. Error when updating a specific custom field
Another possible scenario that may cause posts to be duplicated on every update is when you’re experiencing a custom field error.
Read here how to fix this error.
3. Plugin conflict
Another possible scenario – one of the activated plugins on sub-sites creates this issue. Try to deactivate the plugins one by one and see what will happen. One of the plugins that sometimes may create an issue – Yoast SEO.