I have created a MERN app which was working fine yesterday. Suddenly it started giving "304 Not Modified" error . I tried multiple solutions like clearing cache, opening on private window and even adding this piece of code on my server.js,

app.get("*", function (req, res, next) {
  res.setHeader("Date", new Date().toString());
  next();
});

Still, I cannot get over this issue. Can someone please help me?