Zoom with two fingers initial position

I am trying to use zoom with two fingers but unfortunately whenever I place two fingers together, the starting value of camera.fieldOfView changes drastically. As in it is not able to read the current value. I feel it goes to some other value. It should start from the current value. What am I doing wrong here?

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.InputSystem.EnhancedTouch;
using Touch = UnityEngine.InputSystem.EnhancedTouch.Touch;

public Camera camera;

    float touchDist = 0;
    float lastDist = 0;
    public float maxAngle = 60;
    public float minAngle = 30;

    private void Start()
    {
        EnhancedTouchSupport.Enable();
    }
    public void Update()
    {

        if (Touch.activeFingers.Count == 2)
        {
            Touch activeTouch = Touch.activeFingers[0].currentTouch;

            Touch touch1 = Touch.activeFingers[0].currentTouch;
            Touch touch2 = Touch.activeFingers[1].currentTouch;

            if (touch1.phase == UnityEngine.InputSystem.TouchPhase.Began && touch2.phase == UnityEngine.InputSystem.TouchPhase.Began)
            {
                lastDist = Vector2.Distance(touch1.screenPosition, touch2.screenPosition);
            }

            if (touch1.phase == UnityEngine.InputSystem.TouchPhase.Moved && touch2.phase == UnityEngine.InputSystem.TouchPhase.Moved)
            {
                float newDist = Vector2.Distance(touch1.screenPosition, touch2.screenPosition);
                touchDist = lastDist - newDist;
                lastDist = newDist;

                // Your Code Here
                camera.fieldOfView += touchDist * 0.05f;

                if (camera.fieldOfView > maxAngle)
                {
                    camera.fieldOfView = maxAngle;
                }

                if (camera.fieldOfView < minAngle)
                {
                    camera.fieldOfView = minAngle;
                }

            }
        }

    }

}