Zend certified PHP/Magento developer

API wont work in PHP 7.3.12 but does in 5.6.4, the error is maximum execution time of 30 seconds exceeded, even if I I up this it time it just hangs. This is the line of code PHP is saying is wrong is the problem is below, any ideas?? while (($res = curl_multi_select($mh)) === 0) {};