Firebase auth currentUser is always null

I am trying to protect a route in web app using load function ,reading the value of currentUser from auth to see if the user is logged in but it is always null. So when I refresh the page I am kicked out.

import { auth } from "$lib/firebase";import { redirect } from "@sveltejs/kit";export const load = async () => {    const user = auth.currentUser;    if (!user) {        throw redirect(302, '/login');    }    return {};};

I tried:

1. to use onAuthStateChanged instead and implement a listener.
2. to stop firebase from reinitialize in refreshes.
3. implement a function with await to see if there is delay on vale update.
4. Enforcing firebase persistence mode.
5. It's a +page.ts. And I tried changing the values of ssd and csr as well to know how rendering affect this.

The result was always the same. null as currentUser.