I am building a chat website. Everything works really well except the activity status. At first it seems to work, but sometimes it gets glitchy, especially when a user sends a message. It automatically changes to the previous value (e.g. "online" goes to "10 minutes ago" which is the previous value from the database. I am using JS and Firebase. It has 4 parts that are responsible for the status of activity. Even tho the database contains the good value of activity something in my code is broken that it shows the wrong value.

Here is my code:

// logging and disconnecting
firebase.auth().setPersistence(firebase.auth.Auth.Persistence.SESSION);
firebase.auth().onAuthStateChanged(function (user) {
  if (user)
  {
      currentUser.style.display = "block";
      currentUser.innerHTML += firebase.auth().currentUser.email;
      document.getElementById("logout").style.display = "block";
      username = firebase.auth().currentUser.displayName;

// updating the user's online status
      let connectionsRef = db.ref("status/" + username + "/connections");
      let lastOnlineRef = db.ref("status/" + username + "/lastOnline");
      let connectedRef = db.ref(".info/connected");

      connectedRef.on("value", function (snapshot) {
          if (snapshot.val() === true) {
              const connection = connectionsRef.push();
              connection.onDisconnect().remove();
              connection.set(true);
              lastOnlineRef.onDisconnect().set(firebase.database.ServerValue.TIMESTAMP);
          }
      });
  }
});

// setting user's last-online status (function)
function lastOnline()
{
  let lastOnline = db.ref("status/" + receiver + "/lastOnline");
  lastOnline.on("value", function (snapshot) {
      const lastOnlineDate = snapshot.val();
      const displayedLastOnline = timeSince(lastOnlineDate);
      document.getElementById("status").innerHTML = "last seen: " + displayedLastOnline + " ago";
  });
}

// logging out (function)
function logout()
{
  firebase.auth().signOut().then(() => {
          window.location.replace("./index.html");
  }).catch((error) => {});
}