Head bone snap-looking up while trying to look down

Hello, I want to make a head-neck bone that looks and the camera follows, heres my code

 using UnityEngine;
 using System.Collections;
 
 public class HeadControl : MouseSensitivity {
 
     private float startingRotation;
     private float mouseY;
     public float bendLimit;
     
     void Start () {
         startingRotation = transform.localRotation.x;
         mouseY = startingRotation;
     }
     
     void LateUpdate () {    
         mouseY += Input.GetAxisRaw ("Mouse Y") * ySensitivity * Time.deltaTime;
         mouseY = Mathf.Clamp (mouseY, startingRotation - bendLimit / 2, startingRotation + bendLimit / 2);
         transform.localRotation = Quaternion.Euler (mouseY, 0, 0);
     }
 }

Sometimes, however, my character's head snaps up a little when looking down.

Any ideas? Is it because of LateUpdate?