Why does the camera move 90* on the x-axis when the scene starts?

Question

Unity

Implementing a simple 1st person camera control system. When the scene starts, the camera abruptly drops 90 degrees in X. The same code works fine in the tutorial I copied it from:

using UnityEngine;

public class MouseLook : MonoBehaviour
{
//скорость вращения
    public float mouseSens = 100f;
// игрок
    public Transform playerBody;
// угол вращения по X
    float xRotation = 0f;
    void Start()
    {
// фиксирую курсор в центре
        Cursor.lockState = CursorLockMode.Locked;
    }

    void Update()
    {
// получаю ввод с мышки
        float mouseX = Input.GetAxis("Mouse X") * mouseSens * Time.deltaTime;
        float mouseY = Input.GetAxis("Mouse Y") * mouseSens * Time.deltaTime;

         xRotation -= mouseY;
       // проблема происходит из-за этой строчки кода которая должна ограничивать вращения по оси X
        xRotation = Mathf.Clamp(xRotation, -90f, 90f);

        transform.localRotation = Quaternion.Euler(xRotation, 0f, 0f);
        
        playerBody.Rotate(Vector3.up * mouseX);
    }
}

Answer 1

The default value of xRotation needs to be changed. Perhaps in the example it was public and the value was assigned in the editor.