why isnt this pause menu code working?

the code when it works right should pause the game (which means setting the timescale to 0)when you press esc and bring up a pause menu. it does this, but when i press the menu button( which brings me to the main menu) and then press play(brings me to level 1) the level starts off with a timescale of 0 and i have to press esc for the game to start.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.SceneManagement;

public class PauseMenu : MonoBehaviour
{
    public static bool GameIsPaused = false;

    public GameObject pauseMenuUI;

    void Start()
    {
        pauseMenuUI.SetActive(false);
    }

    // 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 = 1f;
        GameIsPaused = false;
    }

    void Pause()
    {
        pauseMenuUI.SetActive(true);
        Time.timeScale = 0f;
        GameIsPaused = true;
    }

    public void LoadMenu()
    {
        SceneManager.LoadScene("main menu");
    }
}
```