Gameobject flickers on camera follow. Solved but with silly method :/

im making an endless runner game, and everytime I play the game the runner was flickering. But at gameplay when I disable and re-enable the camera follow script component in the camera. the flickering just fixed. so I make a method to disable the camera follow script component at the start of the game and then re-enable it after a certain amount of time just to make the flickers go away. (silly method but works just fine)

I've tried a lot of different way from tweaking the setting to manipulating camera object, but no other solutions. (I even uninstal & re-instal unity ==`)

So I need to know why this is happening, is it a bug? and if there is another solution I'd like to know... I also leave the camera component setting to default.

This is the Player Script

 private CharacterController controller;
 private Float speed = 10;
 private  GameObject camFol;
 private bool moving;
 
 void Start () {
    controller = getComponent<CharacterController> ();
    camFol = GameObject.FindGameobjectWithTag("MainCamera");
    camFol.GetComponent<CameraFollowScript>().enabled = false;
 }
 
 void Update () {
   if (Input.GetKeyDown(KeyCode.Space))
     controller.Move (vector3.forwad * speed * time.deltatime);
     Moving = true;

  if (Moving)
     camFol.GetComponent<CameraFollowScript>().enabled = true;
 }

& this is the Camera follow Script

 private Transform lookAt;
 private vector3 startPosition;
 
 void Start () {
   lookAt = GameObject.FindGameobjectWithTag("Player").transform;
   startPosition = transform.position - lookAt.position;
 }
 
 void Update () {
   transform.position = lookAt.position + startPosition;
 }