enemy shakes when it gets to a certin position

i dont know a lot about unity but im trying to make a game and the enemy has a speacial attack and this is how it should work . if the enemy felt the player he will fly then a danger zone appers then the enemy have to go fast into the danger zone . if the player touches the player he dies . porblem is that when the enemy went into the zone . he started to shake in the x axis heres the attacking part to the enemys AI hope someone responds fast using System.Collections; using System.Collections.Generic; using UnityEngine;

 public class Enemy : MonoBehaviour {
     public GameObject dangerzone;
     private Vector2 movement;
     private Rigidbody2D rb; 
 
     private void Start(){
         rb = GetComponent<Rigidbody2D>();
     }
 
     private void Update(){
         Vector3 direction = dangerzone.transform.position - transform.position;
         direction.Normalize ();
         movement = direction;
         dash (movement);
     }
     void dash(Vector2 direction){
         rb.MovePosition ((Vector2)transform.position + direction * 6 * Time.deltaTime);
     }
 }