joystick does not work properly

i am using joystick in this. when i moves joystick left it faces left but while facing left when i am moving forward it comes back to original position and moves forward i want that when i turn left and then forward i want it moves forward with left direction. Please Help

Here it is my code

public float speed = 2; private Rigidbody rb; public Animator animator; public FixedJoystick joystick; public Camera cam; public float a;

 void Awake()
 {
     rb = GetComponent<Rigidbody>();
 }

 void Update()
 {
     rb.velocity = new Vector3(joystick.Horizontal * speed, rb.velocity.y, joystick.Vertical * speed);
     if (joystick.Horizontal >= .2f || joystick.Horizontal <= -.2f || joystick.Vertical >= .2f || joystick.Vertical <= -.2f)
     {
         animator.SetBool("RunUp", true);
         transform.rotation = Quaternion.LookRotation(rb.velocity);
     }
     else
     {
         animator.SetBool("RunUp", false);
     }
 },if i am moving the player with joysitck left and then my player faces left then when i move forward it automatically turns at its original position and move forward. I want that if my player faces left and i move the joystick up then my player moves forward on left side.

Here it is my code public float speed = 2; private Rigidbody rb; public Animator animator;

 public FixedJoystick joystick;

 public float jump;

 bool isGrounded = false;

 public Camera cam;

 public float a;

 void Awake()
 {
     rb = GetComponent<Rigidbody>();
 }

 void Update()
 {
     rb.velocity = new Vector3(joystick.Horizontal * speed, rb.velocity.y, joystick.Vertical * speed);
     if (joystick.Horizontal >= .2f || joystick.Horizontal <= -.2f || joystick.Vertical >= .2f || joystick.Vertical <= -.2f)
     {
         animator.SetBool("RunUp", true);
         transform.rotation = Quaternion.LookRotation(rb.velocity);
     }
     else
     {
         animator.SetBool("RunUp", false);
     }
 }