Can't get Data while fetching from React Error(304)

While i'm using axios to fetch data it's return 304 on React . But it's work on Postman !

 const [mangas, setMangas] = useState([])
        
          useEffect(() => {
            const getMangas = async () => {
              const res = await axios.get('/mangas')
              setMangas(res.data)
            }
            getMangas()
          }, [])
          console.log(mangas)

::ffff:127.0.0.1 - - [16/Aug/2021:10:34:12 +0000] "GET /api/mangas HTTP/1.1" 304 -

Morgan return this message on React!

  router.get('/', async (req, res) => {
          try {
            const mangas = await Manga.find()
            res.status(200).json(mangas.reverse())
          } catch (err) {
            res.status(500).json(err)
          }
        })

::1 - - [16/Aug/2021:10:34:44 +0000] "GET /api/mangas HTTP/1.1" 200 5763

this is from Postman!

i tried to clear Browser'Cache but it doen't work