Why after changing variable s value it returns at the original value?

Hi, thanks for reading, i'm new to unity and i'm trying to make a 2d game just for learning something on this engine. This code make enemies change direction when they hit a object tagged "Wall", but when i try it enemies still run against wall.

 using UnityEngine;
 using System.Collections;
 
 public class enemiesController : MonoBehaviour {
     Vector3 endposition;
     private float Edirection;
 
     // Use this for initialization
     void Start () {
         Edirection = 1f;
     }
     
     // Update is called once per frame
     void FixedUpdate () {
         print (Edirection);
         endposition.Set (Edirection, 0, 0);
         endposition = endposition * 2 * Time.deltaTime;
         transform.position += endposition;
     }
     void OnCollisionEnter2D(Collision2D other){
         if (other.gameObject.tag == "Wall") {
             Edirection = -1f;
             print("collision");
         }
     }
 }

I tried to put some print functions in and the problem seems to be that Edirection continue to change value after the collision, whitout any new collisions.

screen of console: