Amplify - Federated Sign In - Failed to get user from user pool

I'm working on a react-native / Expo app using Amplify with Cognito for Authentication and Authorization. I have configured Federated Sign On for Facebook and Google+ using the amplify CLI.

I am not using the hosted UI, I have created my own login interface with the respective buttons.

Here is the code for the Facebook Sign-In button:

import { FontAwesome } from '@expo/vector-icons'
import { Auth } from 'aws-amplify'
import * as Facebook from 'expo-facebook'
import React, { Fragment } from 'react'
import { Alert } from 'react-native'
import core from '../../core'

export default () => {
    const handleFBSignIn = async () => {
        try {
            await Facebook.initializeAsync({
                appId: "##################"
            })
            const { type, token, expires } = await Facebook.logInWithReadPermissionsAsync()
            if (type === 'success') {
                const { id, email, name } = await (await fetch(`https://graph.facebook.com/me?access_token=${token}&fields=id,name,email`)).json()
                await Auth.federatedSignIn('facebook', { token, expires_at: expires }, { name, email })
            }
        } catch (ex) {
            await Alert.alert('Facebook Sign in Failed', ex.message, ['Ok'])
        }
    }


    return (
        <core.components.VisionButton
            title={<Fragment><FontAwesome name='facebook' size={16} color='#fff' /> Facebook</Fragment>}
            color='facebook'
            style={{ margin: 6 }}
            onPress={handleFBSignIn}
        />
    )
}

The call to Auth.federatedSignIn(...) succeeds and I get back a FederatedUser

Hub also receives an auth event for signIn

As far as the app is considered, there is now an authenticated user. However, whenever I try to call any AWS resources that require authentication I get No Current User.

I have also noticed that, while the Facebook login is shown in the Cognito Identity Pool, no user is created in the Cognito User Pool.

How do I get a CognitoUser from a Federated Sign In?