Enemy shake/vibrate when following character

I am using the arongranberg A* path finding project to create way points for one enemy to follow the player. However, the enemy vibrates back and forward by about 0.1 - 0.2 unit distance when moving. I have done a lot of research regarding this problem in the past few days but to no avail I could not find a solution that solves it. This is link to a gif to show what I mean.

I have tried,

changing Application.targetFrameRate = 30;

changing fixed update to update and vice versa;

using rigidbody2d and turn interpolate on plus using velocity to move;

turning iskinematic on and off;

using translate to move.

none of the above solution works. Below is the script I have for my enemy. Any advice would be appreciated.

 using UnityEngine; using System.Collections; //Note this line, if it is left out, the script won't know that the class 'Path' exists and it will throw compiler errors //This line should always be present at the top of scripts which use pathfinding using Pathfinding; public class AstarAI : MonoBehaviour { //The point to move to public Transform target; private Seeker seeker; //The calculated path public Path path; //The AI's speed per second public float speed = 200; //The max distance from the AI to a waypoint for it to continue to the next waypoint public float nextWaypointDistance = 0.02f; //The waypoint we are currently moving towards private int currentWaypoint = 0; Rigidbody2D rb; public void Start () { rb = this.GetComponent<Rigidbody2D> (); seeker = GetComponent<Seeker>(); //Start a new path to the targetPosition, return the result to the OnPathComplete function seeker.StartPath( transform.position, target.position, OnPathComplete ); } public void GoToNewTarget(Transform newTarget) { //path = null; currentWaypoint = 0; nextWaypointDistance = 0.02f; target = newTarget; seeker = GetComponent<Seeker>(); seeker.StartPath( transform.position, target.position, OnPathComplete ); } public void OnPathComplete ( Path p ) { Debug.Log( "Yay, we got a path back. Did it have an error? " + p.error ); if (!p.error) { path = p; //Reset the waypoint counter currentWaypoint = 0; } } public void Update () { if (path == null) { //We have no path to move after yet return; } if (currentWaypoint >= path.vectorPath.Count) { Debug.Log( "End Of Path Reached" ); return; } //this.GetComponent<Rigidbody2D> ().MovePosition (path.vectorPath[currentWaypoint]); //Debug.Log (path.vectorPath[currentWaypoint]); //Direction to the next waypoint Vector3 dir = ( path.vectorPath[ currentWaypoint ] - transform.position ).normalized; //GetComponent<Rigidbody2D> ().velocity = new Vector2 (dir.x * 3, dir.y * 3); //Vector3.MoveTowards(transform.position, path.vectorPath[ currentWaypoint ], 2*Time.fixedDeltaTime); dir *= speed* Time.deltaTime; rb.velocity = dir; //this.gameObject.transform.Translate( dir ); //Check if we are close enough to the next waypoint //If we are, proceed to follow the next waypoint if (Vector3.Distance (transform.position, path.vectorPath [currentWaypoint]) < nextWaypointDistance) { currentWaypoint++; return; } } }