Lerping saved position in FixedUpdate causes inconsistent in speed with the reply !

I have a racing game where im saving ghost and sending the said saved ghosts to friends, the problem is when i save the position and rotation in fixed update and play back the saved position in the fixed update the playback is moving to fast than the saved ghost (i.e the replay of the position and rotation is not int he same time span when its saved) i have attached my code down

 void FixedUpdate()
 {

// for playing back the saved positions and rotation

     if(StartGhost)
     {


         check++;

         if (!gameObject.activeSelf)
         {
             gameObject.transform.position = ReadPosition[0];
             gameObject.transform.rotation = ReadRotation[0];
             gameObject.SetActive(true);
         }
         if (check != ReadPosition.Count)
         {

// Tried different lerping and things all same results

             // gameObject.transform.position = Vector3.Slerp(gameObject.transform.position, ReadPosition[check], Time.deltaTime / 0.001f);
             // gameObject.transform.rotation = Quaternion.SlerpUnclamped(gameObject.transform.rotation, ReadRotation[check], Time.deltaTime / 0.02f);
             // PlayerCarInstance.transform.position = Vector3.SmoothDamp(PlayerCarInstance.transform.position, ReadPosition[check], ref testref, 0.2f);
               gameObject.transform.position = Vector3.Lerp(gameObject.transform.position, ReadPosition[check], Time.smoothDeltaTime/0.2f );
            // gameObject.transform.position = ReadPosition[check];
             gameObject.transform.rotation = Quaternion.SlerpUnclamped(gameObject.transform.rotation, ReadRotation[check], Time.fixedDeltaTime / 0.02f);
             //PlayerCarInstance.transform.rotation = ReadRotation[check];

         }
         else
         {
             StartGhost = false;
         }

         

     }

// for saving the ghost

     if(SaveGhost)
     {
         Position.Add(this.transform.position);
         Rotation.Add(this.transform.rotation);

         //Debug.Log (RealPlayer.transform.position.ToString());
         Count++;


         if(carcontroller.Levelended && carcontroller.isIA != false)
         {
             timer -= Time.deltaTime;
             if(timer < 0)
             {
                 Ghostmanager.Position = Position;
                 Ghostmanager.Rotation = Rotation;
                 Ghostmanager.Count = Count;
                 SaveGhost = false;

             }
         }
     }


 }

if any one can point out what im doing wrong it will be helpful ! thanks in advance