tile movement Animation problem

when i click right to move right i get a right walking animation and a right facing animation when I unpress the key which is normal but for a split second (or couple frames) after I unpress the key I get an animation where the player faces up. Does anybody know why that is? this is the code i have.

 using System.Collections.Generic; using UnityEngine;
 public class PlayerMovement : MonoBehaviour { private float moveSpeed = 2f; private float gridSize = 1f;
 private enum Orientation
 {
     Horizontal, Vertical
 };
 private Orientation gridOrientation = Orientation.Vertical;
 private bool allowDiagonals = false;
 private bool correctDiagonalSpeed = true;
 private Vector2 input;
 private bool isMoving = false;
 private Vector3 startPosition;
 private Vector3 endPosition;
 private float t;
 private float factor;
 
 private Animator anim;
 private Vector2 lastMove;
 
 void Start ()
 {
     anim = GetComponent<Animator> ();
 }
 public void Update ()
 {
     if (!isMoving)
     {
         input = new Vector2 (Input.GetAxis ("Horizontal"), Input.GetAxis ("Vertical"));
         if (!allowDiagonals)
         {
             if (Mathf.Abs (input.x) > Mathf.Abs (input.y))
             {
                 input.y = 0;
             }
             else
             {
                 input.x = 0;
             }
         }
 
         if (input != Vector2.zero)
         {
             StartCoroutine (Move (transform));
             lastMove = input; // new.
         }
     }
     anim.SetFloat ("MoveX", Input.GetAxis ("Horizontal"));
     anim.SetFloat ("MoveY", Input.GetAxis ("Vertical"));
     anim.SetFloat ("LastMoveX", lastMove.x);
     anim.SetFloat ("LastMoveY", lastMove.y);
     anim.SetBool ("IsMoving", isMoving);
 }
 public IEnumerator Move (Transform transform)
 {
     isMoving = true;
     startPosition = transform.position;
     t = 0;
 
     if (gridOrientation == Orientation.Horizontal)
     {
         endPosition = new Vector3 (startPosition.x + System.Math.Sign (input.x) * gridSize,
             startPosition.y, startPosition.z + System.Math.Sign (input.y) * gridSize);
     }
     else
     {
         endPosition = new Vector3 (startPosition.x + System.Math.Sign (input.x) * gridSize,
             startPosition.y + System.Math.Sign (input.y) * gridSize, startPosition.z);
     }
     if (allowDiagonals && correctDiagonalSpeed && input.x != 0 && input.y != 0)
     {
         factor = 0.7071f;
     }
     else
     {
         factor = 1f;
     }
     while (t < 1f)
     {
         t += Time.deltaTime * (moveSpeed / gridSize) * factor;
         transform.position = Vector3.Lerp (startPosition, endPosition, t);
         yield return null;
     }
     isMoving = false;
     yield return 0;
 }
 }

Video: https://ezgif.com/video-to-gif/ezgif-1-e62e21f22d.webm