At what point is siteId set for orders?

Question

I have an adjuster I am trying to get to work, but the order has to come from a specific site in order for the adjuster to be applied. The siteId is 2, but when I try to get the siteId from the Order Model I always get one.

public function adjust(Order $order): array
{
    die($order->siteId); // returns 1 no matter what site I created the order on
    if($order->siteId == 2){
        // code here
    }
}

Do I need to be passing the Site Id when creating the order? Or am I possibly messing something up somewhere?