My constructors are initializing with the same, seemingly random incorrect values

Question

I am writing a program that replicates the functionality of the List ADT using arrays; I am beginning by creating a Node object with two attributes: the element and a pointer to the next node. When I run my code, however, it reports that all of my Nodes initialize with element -2 and a random pointer, regardless of how I construct them; does anyone know what could be causing this?

#include <fstream>
#include <iostream>

using namespace std;

/* Class Name: Node
Main Function: Store an element (in this case, a positive integer) and a pointer to the next Node in the List, or to "null" 
Methods: getElement, setElement, getNext, setNext

*/

class Node {
    public:
        int element; //Node has two attributes: an integer, element, and a pointer to a Node, next
        Node* next;
        
        Node(int element, Node* next){ //Node can be constructed with both attributes inputted
            this->element = element;
            this->next = next;
        }
        
        Node (int element){ //If only one is inputted, then
            this->element = element;
            next = nullptr; //the "next" pointer is initialized as "NULL"
        }
        
        Node (Node* next){
            element = 0; //or the node is initialized with an element of "0"
            this-> next = next;
        }
        
        Node(){
            int element = 0; //the Node can also be constructed given no input, using both default values
            Node* next = nullptr; 
        }
            
        
        /* Method Name: getElement
        Input Parameters: N/A
        Return Values: element, the value stored by the node
        Main Function: Returns the element stored by the node
        
        */
        
        int getElement() {
            return element;
        }
        
        /* Method Name: setElement
        Input Parameters: A new element to store in the Node
        Return Values: the original element being stored, if the method executes correctly; -1, if method encounters an error
        Main Function: Sets the node's element to a new value after checking if it is positive
        
        */
        
        int setElement (int newElement){
            if (newElement <= 0){
                cerr << "Error: this List can only store positive integers." << endl << endl;
                return -1;
            }
            int oldElement = element;
            element = newElement;
            return oldElement;
        }
        
        /* Method Name: getNext
        Input Parameters: N/A
        Return Values: next, a pointer to the next Node in the List
        Main Function: Reads a file and stores its contents as an array of integers; reports if an error occurs
        
        */
        
        Node* getNext() {
            return next;
        }
        
        /* Method Name: setNext
        Input Parameters: A new pointer for the Node to direct to
        Return Values: the original pointer being stored, if the method executes correctly; -1, if method encounters an error
        Main Function: Sets the node's element to a new value after checking that the node it points to exists
        
        */
        
        Node* setNext (Node* newNext){
            Node* oldNext = next;
            next = newNext;
            return oldNext;
        }
        
        
};


int main(){
    
    Node n1; //tests if a Node can be constructed given no input
    cout << "When a node is constructed with no input, it has an element of " << n1.getElement() << " and a next of " << n1.getNext() << endl << endl;
    
    
    Node n2 (5); //tests if a Node can be constructed given an element as input
    cout << "When a node is constructed with element 5, it has an element of " << n2.getElement() << " and a next of " << n2.getNext() << endl << endl;
    
    
    Node n3 (&n1); //tests if a Node can be constructed given an address as input
    cout << "When a node is constructed pointing to Node 1, it has an element of " << n3.getElement() << " and a next of " << n3.getNext(); 
    cout << ", which points to " << n3.getNext()->getElement() << endl << endl;
    
    
    Node n4 (10, &n2); //tests if a Node can be constructed given an element and an address as unput
    cout << "When a node is constructed with element 10 pointing to Node 2, it has an element of " << n4.getElement() << " and a next of " << n4.getNext(); 
    cout << ", which points to " << n4.getNext()->getElement() << endl << endl;
    
    return 0;
}

I was expecting the program to construct four nodes: one with element 0 and a nullptr, one with element 5 and a null pointer, one with element 0 pointing to node 1 and one with element 10 pointing to node 2.