My Quaternion rotation happens instantly

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 
 public class MoveCamera : MonoBehaviour
 {
     private Vector3 Target;
     private Vector3 cameraStartPosition;
     private bool isLerping;
     public float Speed;
     public float speed;// Quaternion speed
 
     public float timer;
     public float CameraPanTime;
 
     public Quaternion targetRotation;
 
     void Start()
     {
         CameraPosition1();
         CameraPosition2();
     }
     public void CameraPosition1()
     {
         isLerping = true;
         cameraStartPosition = transform.position;
         Target = new Vector3(30f, 2.5f, -5f);
   
     }
     public void CameraPosition2()
     {
         isLerping = true;
         cameraStartPosition = transform.position;
         Target = new Vector3(30f, 15f, 200f);
         
     }
     void FixedUpdate()
     {
         if (isLerping)
         {
             timer += Time.deltaTime;
             transform.position = Vector3.Lerp(cameraStartPosition, Target, timer / CameraPanTime);
             transform.rotation = Quaternion.Slerp(transform.rotation, targetRotation, Time.time / CameraPanTime);
         }
     }
 }

Here is my script for my camera to lerp between 2 positions, but when I start the game my camera rotation instantly changes. Whats the issue?