在reactjs中刷新页面时丢失状态值

我想通过Reaction获取用户令牌.我在我的登录提交表单中使用以下代码，它是可以的: 在Login.jsx中:

const Login = () => {

const { setUserToken } = useContext(AppContext);

const submitForm = async (values) => {

        postUserLogin(values)
            .then((response) => {
                const { token } = response.data;
                setUserToken(token);
                setApiError({ status: '', error: '' });
                navigate('/employer/jobs');
            })
            .catch((err) => {
                setUserToken('');
             
            });
     return (<>...</>);
export default Login;

在EmployerJob.jsx中:

const EmployerJob = () => {

const { employerJobs, setEmployerJobs, userToken} = useContext(AppContext);

useEffect(() => {
    const fetchData = async () => {
        const res = await getEmployerJobList(userToken);
        if (res.status === 200) {
            const { paginator, items: jobs } = res.data;
            setPaginatorInfo(paginator);
            setEmployerJobs(jobs);
        }


    }
    fetchData();
}, []);

return (
    <div className="text-light my-4">

        {
            <span>Length: {paginatorInfo.count}</span>
        }

        {
            employerJobs.length > 0 ? employerJobs.map((job, index) => (
                <p key={index}>{job.salary}</p>
            )) : <p>No Job!</p>
        }



      </div>
    );
};

export default EmployerJob;

在appConext.jsx中:

import {createContext} from 'react';

export const AppContext = createContext({
    userToken:'',
    setUserToken:()=>{},
    employerJobs:[],
    setEmployerJobs:()=>{},
});

在App.js中:

const App= ()=> {

  const [userToken, setUserToken] = useImmer('');
  const [employerJobs, setEmployerJobs] = useImmer([]);
  
  return(
    <AppContext.Provider value={{
      userToken,
      setUserToken,
      employerJobs,
      setEmployerJobs,
    }}>
    <div className='App'>
        <Navbar/>
        <Routes>
          <Route path='/employer/login' element={<Login/>} />
          <Route path='/employer/jobs' element={<EmployerJob/>}/>
          <Route path="*" element={<NotFound/>}/>
        </Routes>
    </div>
    </AppContext.Provider>
  );
}

export default App;

它只适用于第一次登录，但当我刷新‘/Employer/Jobs’页面时，userToken值为空.我是新手，我认为不应该更改用户令牌.为什么会这样？我该如何解决这个问题？