My 2D avatar is disappearing suddenly whenever I am moving left or right

Hello everyone,

Can someone please help me with this problem? Basically my 2D Avatar is disappearing suddenly while trying to move in left or right direction with below code:

 public float speed;
 private float input;
 
 Rigidbody2D rb;
 Animator anim;


 // Start is called before the first frame update
 void Start()
 {
     anim = GetComponent<Animator>();
     rb = GetComponent<Rigidbody2D>();

 }

 private void Update()
 {
     if(input != 0)
     {
         anim.SetBool("isRunning", true);
     }
     else
     {
         anim.SetBool("isRunning", false);
     }


     if (input > 0)
     {
         transform.eulerAngles = new Vector3(0, 0, 0);  
     }
     else if (input < 0)
     {
         transform.eulerAngles = new Vector3(0, 180, 0);         }
 }

 // Update is called once per frame
 void FixedUpdate()
 {
     //storing player's input 
     input = Input.GetAxisRaw("Horizontal");

     //Moving player
     rb.velocity = new Vector2(input * speed, rb.velocity.y);
     
 }

Thanks in advance :)