private void FixedUpdate()
    {
        isGrounded = Physics2D.OverlapCircle(groundCheck.position, checkRadius, whatIsGround);

        if (JumpEnemy == false)
        {
            rb.velocity = new Vector2(Input.GetAxis("Horizontal") * speed, rb.velocity.y);
        } else
        {
            JumpEnemy = false;
        }
....
    }

     private void OnTriggerEnter2D(Collider2D collision)
    {

        if (this.CompareTag("Player") && collision.CompareTag("Damage"))
        {
            JumpEnemy = true;
        }
...
    }