Session is not preserved when opening a new tab - React + Node.js

Question

In my React + Node.js app, when a user is logged in, they can interact with the website, visit various pages, and everything works well - as long as the user stays on the same tab. Once opening a new tab (there are links on the website designed to open in a new tab), the user is redirected to the public home page, as if they are not logged in. Based on debugging, the redirection is done by a middleware, which is called on every authenticated route:

function checkLoggedIn(req, res, next) {
  if (req.session && req.session.username) {
    next();
  } else {
    res.redirect("/");
  }
}

The issue is with req.session, that is not preserved when opening a new tab. I tried to log the req.sessionID, and it seems that the id is preserved when viewing other pages and doing various actions, but when opening a new tab - a new sessionID is set, and then when the user is redirected to the public home page, the original sessionID is printed again.

I should mention that in localhost this works fine. However, in production - it doesn't.

For sessions I use express-session.

Opening the new tab is done on the frontend using the following function:

const visitPage = (username) => {
    window.open(`/details/${username}`, "_blank", "noopener,noreferrer");
  };

Relevant code from app.js:

const port = process.env.PORT || 8000;
app.use(
  cors({
    origin: `${process.env.REACT_APP_URL}`, 
    credentials: true, // Allow (cookies) to be sent
  })
);

/* ... route requires ... */

app.use(express.json());
app.use(express.urlencoded({ extended: false }));

app.use(
  session({
    secret: process.env.SESSION_SECRET,
    resave: false,
    saveUninitialized: true,
    cookie: {
      httpOnly: true,
      secure: true,
      sameSite: "None",
      maxAge: 1000 * 60 * 60,
    },
  })
);

/* ... routes ... */

I'd appreciate any advice regarding getting the new tab to preserve the session, and keep the user in the logged in area of the website.

Thanks in advance