Astar Pathfinding ai moves more nodes than it should

Hi, I am trying to make a grid-based ai for a 2D turn based game using AronGranberg's Astar unity package and the unity pathfinding extension. The ai moves in a grid, but it will skip a node sometimes and move 2 nodes instead of 1. I want it to only move 1 node during its turn.

here are my grid settings.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Pathfinding;

public class enemyAi : MonoBehaviour {

 public Transform target;

 public float speed = 400f;
 public float nextWaypointDistance = 3f;
 Path path;
 int currentWaypoint = 0;
 bool reachedEndOfPath = false;

 Seeker seeker;
 Rigidbody2D rb;

 gameManager gameMan;

 public float stoppingDistance;
 GraphNode node;

 // Start is called before the first frame update
 void Start()
 {
     gameMan = FindObjectOfType<gameManager>();
     seeker = GetComponent<Seeker>();
     rb = GetComponent<Rigidbody2D>();
     InvokeRepeating("updatePath", 0f, 0.5f);
 }

 void updatePath()
 {

     if (seeker.IsDone())
     {
         node = AstarPath.active.GetNearest(transform.position).node;
         seeker.StartPath(rb.position, target.position, onPathComplete);
     }
 }

 void onPathComplete(Path p)
 {
     if (!p.error)
     {
         path = p;
         currentWaypoint = 0;
     }
 }

 // Update is called once per frame
 void FixedUpdate()
 {
     float distanceFromTarget = Vector3.Distance(gameObject.transform.position, target.position);

     if (path == null)
     {
         return;
     }

     if (currentWaypoint >= path.vectorPath.Count)
     {
         reachedEndOfPath = true;
         return;
     }
     else
     {
         reachedEndOfPath = false;
     }

     Vector2 direction = ((Vector2)path.vectorPath[currentWaypoint]);
     Vector2 force = direction * speed * Time.fixedDeltaTime;
     float distance = Vector2.Distance(rb.position, path.vectorPath[currentWaypoint]);


     if (gameMan.isPlayerTurn == false)
     {
         rb.MovePosition(direction);
         if (distance < nextWaypointDistance)
         {
             rb.velocity = Vector2.zero;
             gameMan.isPlayerTurn = true;
         }

     }

     if (distance < nextWaypointDistance)
     {
         currentWaypoint++;
     }
 }

}

and this is my ai script.

If you know why the ai is doing this, I would appreciate a reply.