Help with pathfinding function!

Hey everyone. Can someone help me poiting some errors in this Pathfinding function?

This is just breaking Unity.

 void AStar (Node initialNode, Node finalNode) {
     
             openList = closedList = new List<Node>();
             
             initialNode.G = 0;
             initialNode.H = initialNode.GetH( finalNode );
             
             openList.Add(initialNode);
         
             Node current = null;
         
             while(openList.Count != 0) {
             
                 current = openList[0];
                 closedList.Add(current);
             
                 if(current == finalNode) {
                 
                     reconstructPath(openList);
                     return;
                 
                 }
             
                 foreach(Node neighbor in current.Neighbors) {
                 
                     if(closedList.Contains(neighbor)) {
                     
                     continue;
                     
                     } else {
                     
                     if(!openList.Contains(neighbor)) {
                     
                         neighbor.defineParentNode(current);
                         neighbor.GetF(current, finalNode);
                         openList.Add(neighbor);
                         
                         } else {
                         
                             int neighborG = neighbor.GetG(current);
                         
                             if(neighborG < neighbor.G) {
                             
                                 neighbor.defineParentNode(current);
                                 neighbor.G = neighborG;
                             
                             }
                         }
                     }
                 }
             
                     openList.Sort(delegate(Node x, Node y) {
                         
                         return x.F.CompareTo(y.F);
             
             });
         }
     }

And here's the Node class :

 public class Node {
 
     public Vector3 position;
     public List<Node> Neighbors; // these are defined with a function that I omitted, but I'm sure that it doesn't return a empty list
     public Node parentNode;
     
     public int F, G, H;
     
     public Node (Vector3 Position, bool DefineNeighbors) {
         
         position = Position;
         
     }
     
     
     public int GetF (Node currentNode, Node finalNode) {
         
         this.G = GetG(currentNode);
         this.H = GetH(finalNode);
         
         this.F = this.G + this.H;
         
         return this.F;
         
     }
     
     public int GetH (Node finalNode) {
         
         H = (int)(Mathf.Abs(this.position.x - finalNode.position.x) + Mathf.Abs(this.position.z + finalNode.position.z));
         return H;
         
     }
     
     public int GetG (Node currentNode) {
         
         int distanceToCurrent = (int)(Mathf.Abs(this.position.x - currentNode.position.x) + Mathf.Abs(this.position.z + currentNode.position.z));
         G = currentNode.G + distanceToCurrent;
         
         return G;
         
     }
     
     
     public void defineParentNode(Node parent) {
         
         this.parentNode = parent;
         
     }
 
     
 }

If someone have the time to read the code and point something that could be make me get stuck in the loop, I'll appreciate!

Thanks from now!