Cannot add calendar to a real iOS device when it works on an iOS simulator

I'm using Expo's Calendar API to create a calendar and events, but I'm getting the following error only on my real device when it works perfectly on the iOS simulator:

[Unhandled promise rejection: Error: Error: Calendar 'Expo Calendar' could not be saved: Error Domain=EKErrorDomain Code=17 "That account does notallow calendars to be added or removed." UserInfo={NSLocalizedDescription=That account does not allow calendars to be added or removed.}]

My code:

import React, { useEffect } from 'react';
import { View, Text, Button, Platform } from 'react-native';
import * as Calendar from 'expo-calendar';

export default function App() {
  useEffect(() => {
    (async () => {
      const { status } = await Calendar.requestCalendarPermissionsAsync();
      if (status === 'granted') {
        const calendars = await Calendar.getCalendarsAsync();
        console.log('Here are all your calendars:');
        console.log({ calendars });
      }
    })();
  }, []);

  return (
    <View
      style={{
        flex: 1,
        backgroundColor: '#fff',
        alignItems: 'center',
        justifyContent: 'space-around',
      }}>
      <Text>Calendar Module Example</Text>
      <Button title="Create a new calendar" onPress={createCalendar} />
    </View>
  );
}

const getDefaultCalendarSource = async () => {
    const defaultCalendar = await Calendar.getDefaultCalendarAsync();
    return defaultCalendar.source;
}

async function createCalendar() {
  const defaultCalendarSource =
    Platform.OS === 'ios'
      ? await getDefaultCalendarSource()
      : { isLocalAccount: true, name: 'Expo Calendar' };
  const newCalendarID = await Calendar.createCalendarAsync({
    title: 'Expo Calendar',
    color: 'blue',
    entityType: Calendar.EntityTypes.EVENT,
    sourceId: defaultCalendarSource.id,
    source: defaultCalendarSource,
    name: 'internalCalendarName',
    ownerAccount: 'personal',
    accessLevel: Calendar.CalendarAccessLevel.OWNER,
  });
  console.log(`Your new calendar ID is: ${newCalendarID}`);
}

The permission have been given to the calendar and all the calendars have "allowsModifications": true, but can't understand why it says it's not allowed only on a real device.

I've tried modifying the default calendars to different source as following:

async function getDefaultCalendarSource() {
  const calendars = await Calendar.getCalendarsAsync();
  const defaultCalendars = calendars.filter(
    each => each.source.name === 'Gmail' // or 'iCloud', 'Yahoo'
  );
  return defaultCalendars[0].source;
}

thinking that it may have to do with the source, but they result in the same error, "that account does not allow calendars to be added or removed."