Create new lead $event->isNew() return false

Development
1

Your software
My Mautic version is: 5.0.0
My PHP version is: 8.1.2

My question
The log output confirms that the event is being triggered, but the isNew() condition is evaluating as false, meaning the contact is not considered “new” by Mautic at the point when this event is fired.

public static function getSubscribedEvents()
    {
        return [
            LeadEvents::LEAD_POST_SAVE => 'onContactSave',
        ];
    }

    public function onContactSave(LeadEvent $event)
    {
        $logFile = '/var/www/html/mautic/var/logs/Plugin_log.txt';
        file_put_contents($logFile, 'onContactSave triggered' . PHP_EOL, FILE_APPEND);

	$lead = $event->getLead();
    	file_put_contents($logFile, 'Lead ID: ' . $lead->getId() . PHP_EOL, FILE_APPEND);
if ($event->isNew()) {
        file_put_contents($logFile, 'New contact created: ' . $lead->getName() . PHP_EOL, FILE_APPEND); // Log when the new contact is detected
    } else {
        file_put_contents($logFile, 'This is not a new contact.' . PHP_EOL, FILE_APPEND); // Log if the contact is not new
    }