NodeJs stop receiving post requests after 6 requests

Question

I am trying to use navigator.sendBeacon() when user is inactive. At the same time I will be sending to server side when user is inactive.

If I switch from the browser after the 6th sent beacon, my backend don't take the requests.

Client side:

  document.addEventListener("visibilitychange", () => {
    if (document.visibilityState === "visible") {
      const status = JSON.stringify({ status: "user is online" });
      navigator.sendBeacon(
        "http://localhost:5000/api/user/user-status",
        status
      );
    } else {
      const status = JSON.stringify({ status: "user is offline" });
      navigator.sendBeacon(
        "http://localhost:5000/api/user/user-status",
        status
      );
    }
  });

Server side:

userRouter.post("/user-status", async (request, response) => {
  const body = request.body;

  if (body) {
    const obj = JSON.parse(body);
    console.log("this is body:", obj);
  }
});

To start console.log again in server side, I have to restart the server, otherwise it won't log anything.