Using Constructor v/s static method for basic linked list

Question

I've tried implementing a basic linked list in my first try I implemented a static method (insert) for inserting data and pointer to the next element like shown below:

#include <iostream>


using namespace std;

class Node{
    public:
        int data = NULL;
        Node* next = nullptr;
        Node(){}
        
        static void insert(int data, Node* next,Node* obj){
            obj->data = data;
            obj->next = next;
        }
        static void printList(Node* n){
            while(n != nullptr){
                cout << n->data << " ";
                n = n->next;
            }
        }
};




int main()
{
    Node* head = nullptr;
    Node* second = nullptr;
    Node* third = nullptr;
    head = new Node();
    second = new Node();
    third = new Node();
    
    

    //via static method
    Node::insert(1,second,head);
    Node::insert(2,third,second);
    Node::insert(3,nullptr,third);
    
    Node::printList(head);
    
    delete head;
    delete second;
    delete third;
    return 0;
}

it's working fine as I expect (getting output as 1 2 3), but when I implement it using constructors like show below:

#include <iostream>


using namespace std;

class Node{
    public:
        int data = NULL;
        Node* next = nullptr;
        Node(){}
        Node(int data, Node* next){
             this->data = data;
             this->next = next;
        }
        
        static void printList(Node* n){
            while(n != nullptr){
                cout << n->data << " ";
                n = n->next;
            }
        }
};




int main()
{
    Node* head = nullptr;
    Node* second = nullptr;
    Node* third = nullptr;
    

    //via constructors.
    head = new Node(1,second);
    second = new Node(2,third);
    third = new Node(3,nullptr);
    
    Node::printList(head);
    
    delete head;
    delete second;
    delete third;
    return 0;
}

I am getting the output as 1 0. When I call constructor from third to head it's working fine (by that I mean)

third = new Node(3,nullptr);
second = new Node(2,third);
head = new Node(1,second);

Kindly explain why is it behaving like that. Note: I am a beginner in programming.