Top-Down Enemy Ai Animation

Hello, making a top-down 2D game, for my enemy ai animation, change the sprite without rotation, the code works fine, however does not identify all the "if" inside the "if (playerDistance <7f && playerDistance> 1.5f) "If I change the position of" if (currentPosition.lastPosition) "the ones that did not work start working and the previous ones do not work, usually the last 2 work. Should I enter some magnitude of the vectors? How to do this? Grateful.

 public class Ai : MonoBehaviour {
 
 public Transform player;
 public float playerDistance;
 public float moveSpeed;
 public Transform target;
 private Rigidbody2D myRigidbody;
 private bool moving;
 public float timeBetweenMove;
 private float timeBetweenMoveCounter;
 private float timeToMoveCounter;
 public float timeToMove;
 private Vector3 moveDirection;
 public float waitToReload;
 private bool reloading;
 private GameObject thePlayer;
 private Animator anim;
 private Vector2 lastMove;
 private Vector2 currentPosition;
 private Vector2 lastPosition;

 void Start () {
     timeBetweenMoveCounter = Random.Range(timeBetweenMove * 1.25f, timeBetweenMove * 1.25f);
     timeToMoveCounter = Random.Range(timeBetweenMove * 1.25f, timeBetweenMove * 1.25f);
     myRigidbody = GetComponent<Rigidbody2D>();
     reloading = false;
     anim = GetComponent<Animator>();
     currentPosition = transform.position;
     lastPosition = currentPosition;
 }

 void Update () {

     moving = false;

     playerDistance = Vector2.Distance (player.position, transform.position);

     if (playerDistance < 7f && playerDistance > 1.5f) {
         moving = true;
         transform.position = Vector3.MoveTowards (transform.position, player.position, Time.deltaTime * moveSpeed);
         if (currentPosition.x > lastPosition.x) {
             lastMove = new Vector2 (1f, 0f);
         }
         if (currentPosition.x < lastPosition.x) {
             lastMove = new Vector2 (-1f, 0f);
         }
         if (currentPosition.y > lastPosition.y) {
             lastMove = new Vector2 (0f, 1f);
         }
         if (currentPosition.y < lastPosition.y) {
             lastMove = new Vector2 (0f, -1f);
         }
     } else if (playerDistance > 7f) {
         //chase ();
     }

     lastPosition = currentPosition;
     currentPosition = transform.position;
         
     anim.SetFloat ("MoveX", lastMove.x);
     anim.SetFloat ("MoveY", lastMove.y);
     anim.SetBool ("moving", moving);
     anim.SetFloat ("LastMoveX", lastMove.x);
     anim.SetFloat ("LastMoveY", lastMove.y);
 }