PHP Warning: fsockopen

could you please create a php script and put it at same dir as your wp-config.php , with code below

<?php
require( './wp-load.php' );

$response = wp_remote_get( 'https://node17.quic.cloud' );

echo '<pre>';
var_dump($response);
echo '</pre>';

and open it by browser, see what it returns ?

yes , you can create a new php file on your computer , copy-paste above code , then upload it