onAuthStateChanged callback takes a long time to be triggered in Firebase authentication OIDC provider with Auth0

[DevYuns]

HI.

I'm trying to connect firebase auth with auth0 with OIDC provider on react.

The connection is ok, but The callback in onAuthStateChanged takes a long time(about 3 sec or more) to be triggered.

env

"firebase": "^9.12.1",
"react": "^18.2.0",
"react-dom": "^18.2.0",
"react-router-dom": "^6.4.2",
"recoil": "^0.7.5"

logIn function

  const provider = new OAuthProvider('oidc.auth0');

  const onLogin = async (e): Promise<void> => {
      await signInWithRedirect(auth, provider);
  };

onAuthStateChanged callback (in recoil effects)

effects: [
    ({onSet, setSelf, resetSelf}) => {
      const t0 = performance.now();

      const unsubscribe = auth.onAuthStateChanged(async (user) => {
        const t1 = performance.now();
        console.log(
          `callback is triggered in ${((t1 - t0) / 1000).toFixed(2)} seconds.`, // about 3 or more sec!!!
        );
      });
      return unsubscribe;
    },
  ],

Any suggestions would be appreciate.