React native app through Expo, getting firestore permission error: - ios

Question

This is my first post here so please let me know if I'm not posting this correctly.
I keep getting the following error in the debug logs of my react native Expo app on the iOS simulator when I have an authenticated user trying to retrieve a firestore document:
FirebaseError: [code=permission-denied]: Missing or insufficient permissions.
Here is firebase.js config file:
import "firebase/firestore";
import "firebase/storage";
import * as firebase from 'firebase';
// Initialize Firebase
const firebaseConfig = {
apiKey: ... //removed for this post, but it is correct and validated
};
firebase.initializeApp(firebaseConfig);
const db = firebase.firestore();
const auth = firebase.auth();
export { auth };
export default db;
Here is my App.js:
import React, { useEffect, useState } from 'react';
import db, { auth } from './firebase';
const getUserData = async(uid) => {
try {
const doc = await db.collection('users').doc(uid).collection('info').doc(uid).get();
if (doc.exists) {
console.log(doc.data());
} else {
// doc.data() will be undefined in this case
console.log("No user info was found for the authenticated user");
}
} catch(err) {
console.log(err);
}
};
useEffect(() => {
auth.onAuthStateChanged((authUser) => {
if (authUser) {
//user is logged in
getUserData(authUser.uid); //retrieve the user's profile data
} else {
//user is logged out
auth.signOut();
}
});
}, []);
My security rules shouldn't be the problem because it works for my web react app with the same logic and user, and the get request is only sent when there is a uid because the user is authenticated. I've printed out the uid after onAuthStateChanged and it is the correct uid.
//Security Rules in Firestore
rules_version = '2';
service cloud.firestore {
match /databases/{database}/documents {
function signedInAndSameUser(uid) {
return request.auth != null && request.auth.uid == uid;
}
match /users/{uid} {
allow read: if request.auth != null;
match /private/{privateId} {
allow read: if signedInAndSameUser(privateId);
}
}
I've seen similar posts that recommended to downgrade to firebase#4.6.2 but I also ran into issues and couldn't get it to work. I'm wondering if firebase still hasn't fixed this issue even after version 8 (In react native app (through Expo) using firestore permissions - request.auth is always null)
This is my current firebase and expo version in my package.json:
//package.json
"expo": "~41.0.1",
"firebase": "8.2.3",
Thank you so much if you can help, I've been stuck on this issue for many hours and can't seem to understand why this works in my react.js web app, but the same logic, user, and security rules won't work in my react native Expo iOS app.