camera doesnt follow player after I added networkIdentiy and networkTransform to the player

(I'm a newbie. I made this game following youtube tutorials. doesnt know a thing about programing.)

so first I made single player game and added following script to the camera and it followed player just fine.

 public GameObject Player;
 public Vector3 offset;

 void Update()
 {
     transform.position = Player.transform.position + offset;
 }

I attached this script to camera and assigned player to public gameobject player. it did follow player, until I added networkidentity and networkTransform because I want to make multiplayer game. and it suddenly stopped following player.
what changes do I need to make to make camera follow player? do I need to change the script or add component to the camera? thank you in advance.