Player Camera still moving when paused

Whenever I hit escape to pause my game, the camera moves as I move the mouse to select an option on the menu. Since I didn't make the first person character myself, I'm not sure where the script for the camera is or how to modify it to freeze when the game is paused. I'll include both the Pause menu script I wrote and the portion of the first person controller script where I believe the camera control is stored as well. Let me know what needs to change in which script, or if there is a different script I should be modifying.

Pause Menu Script:

 using System.Collections;
 using System.Collections.Generic;
 using UnityEngine;
 using UnityEngine.SceneManagement;
 
 public class PauseMenu : MonoBehaviour
 {
     public static bool GameIsPaused = false;
 
     public GameObject pauseMenuUI;
 
     // Update is called once per frame
     void Update() {
         if (Input.GetKeyDown(KeyCode.Escape))
         {
             if (GameIsPaused)
             {
                 Resume();
             } else
             {
                 Pause();
             }
         }
     }
 
     public void Resume ()
     {
         pauseMenuUI.SetActive(false);
         Time.timeScale = 1.0f;
         GameIsPaused = false;
     }
 
     void Pause ()
     {
         pauseMenuUI.SetActive(true);
         Time.timeScale = 0f;
         GameIsPaused = true;
     }
 
     public void QuitGame()
     {
         Debug.Log("Landing...");
         Application.Quit();
     }
 }

First Person Character Controller - Camera:

 using UnityEngine;
 #if ENABLE_INPUT_SYSTEM && STARTER_ASSETS_PACKAGES_CHECKED
 using UnityEngine.InputSystem;
 #endif
 
 namespace StarterAssets
 {
     [Header("Cinemachine")]
         [Tooltip("The follow target set in the Cinemachine Virtual Camera that the camera will follow")]
         public GameObject CinemachineCameraTarget;
         [Tooltip("How far in degrees can you move the camera up")]
         public float TopClamp = 90.0f;
         [Tooltip("How far in degrees can you move the camera down")]
         public float BottomClamp = -90.0f;
 
         // cinemachine
         private float _cinemachineTargetPitch;
 
         // player
         private float _speed;
         private float _rotationVelocity;
         private float _verticalVelocity;
         private float _terminalVelocity = 53.0f;
 
         // timeout deltatime
         private float _jumpTimeoutDelta;
         private float _fallTimeoutDelta;
 
     
 #if ENABLE_INPUT_SYSTEM && STARTER_ASSETS_PACKAGES_CHECKED
         private PlayerInput _playerInput;
 #endif
         private CharacterController _controller;
         private StarterAssetsInputs _input;
         private GameObject _mainCamera;
 
         private const float _threshold = 0.01f;
 
         private bool IsCurrentDeviceMouse
         {
             get
             {
                 #if ENABLE_INPUT_SYSTEM && STARTER_ASSETS_PACKAGES_CHECKED
                 return _playerInput.currentControlScheme == "KeyboardMouse";
                 #else
                 return false;
                 #endif
             }
         }
 
         private void Awake()
         {
             // get a reference to our main camera
             if (_mainCamera == null)
             {
                 _mainCamera = GameObject.FindGameObjectWithTag("MainCamera");
             }
         }
 
         private void Start()
         {
             _controller = GetComponent<CharacterController>();
             _input = GetComponent<StarterAssetsInputs>();
 #if ENABLE_INPUT_SYSTEM && STARTER_ASSETS_PACKAGES_CHECKED
             _playerInput = GetComponent<PlayerInput>();
 #else
             Debug.LogError( "Starter Assets package is missing dependencies. Please use Tools/Starter Assets/Reinstall Dependencies to fix it");
 #endif
 
             // reset our timeouts on start
             _jumpTimeoutDelta = JumpTimeout;
             _fallTimeoutDelta = FallTimeout;
         }
 
         private void Update()
         {
             JumpAndGravity();
             GroundedCheck();
             Move();
         }
 
         private void LateUpdate()
         {
             CameraRotation();
         }
 
         private void GroundedCheck()
         {
             // set sphere position, with offset
             Vector3 spherePosition = new Vector3(transform.position.x, transform.position.y - GroundedOffset, transform.position.z);
             Grounded = Physics.CheckSphere(spherePosition, GroundedRadius, GroundLayers, QueryTriggerInteraction.Ignore);
         }
 
         private void CameraRotation()
         {
             // if there is an input
             if (_input.look.sqrMagnitude >= _threshold)
             {
                 //Don't multiply mouse input by Time.deltaTime
                 float deltaTimeMultiplier = IsCurrentDeviceMouse ? 1.0f : Time.deltaTime;
                 
                 _cinemachineTargetPitch += _input.look.y * RotationSpeed * deltaTimeMultiplier;
                 _rotationVelocity = _input.look.x * RotationSpeed * deltaTimeMultiplier;
 
                 // clamp our pitch rotation
                 _cinemachineTargetPitch = ClampAngle(_cinemachineTargetPitch, BottomClamp, TopClamp);
 
                 // Update Cinemachine camera target pitch
                 CinemachineCameraTarget.transform.localRotation = Quaternion.Euler(_cinemachineTargetPitch, 0.0f, 0.0f);
 
                 // rotate the player left and right
                 transform.Rotate(Vector3.up * _rotationVelocity);
              }