To trigger the processing of background tasks, such as queued feeds, the plugin uses the wp_remote_post function to send a request to your site’s Ajax endpoint (/wp-admin/admin-ajax.php).
The core log indicates that the request is timing out, which will prevent the background tasks being processed.
2023-10-27 14:54:31.382168 - DEBUG → GF_Background_Process::dispatch(): Unable to dispatch tasks to Admin Ajax: cURL error 28: Operation timed out after 1000 milliseconds with 0 bytes received
This is covered by the following page of the documentation: