Cannot read events from Event Hub

I am trying to read events from Event Hub using Azure Active Directory. I can successfully write events to my Hub after authenticating, however when reading my program returns 0 events. I can see that my Hub has got messages waiting and If I read from the Hub using the Shared Access Policy URL I can get my messages.

Here is my program:

using System;
using System.Configuration;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Azure.EventHubs;
using Microsoft.Identity.Client;

namespace EventHubsSenderReceiverRbac
{
    class claimInfo
    {
        public string providerID
        {
            get;
            set;
        }
        public string data1
        {
            get;
            set;
        }
        public string patientId
        {
            get;
            set;
        }
    }
    class Program
    {
        static readonly string TenantId = ConfigurationManager.AppSettings["tenantId"];
        static readonly string ClientId = ConfigurationManager.AppSettings["clientId"];
        static readonly string EventHubNamespace = ConfigurationManager.AppSettings["eventHubNamespaceFQDN"];
        static readonly string EventHubName = ConfigurationManager.AppSettings["eventHubName"];
        private const int numOfEvents = 5;

        static async Task Main()
        {
            var ehClient = generateClient();
            Console.WriteLine("Press s to send {0} events\n", numOfEvents);
            Console.WriteLine("Press r to receive events\n");
            Console.WriteLine("Press any other key to exit\n");
            var userInput = Console.ReadKey();
            Console.WriteLine("\n");
            switch (userInput.Key)
            {
                case ConsoleKey.S:
                    await sendEvents(ehClient);
                    break;
                case ConsoleKey.R:
                    await receiveEvents(ehClient);
                    break;
                default:
                    Console.WriteLine("Return");
                    return;
            }
        }

        static EventHubClient generateClient()
        {
            TokenProvider tp = TokenProvider.CreateAzureActiveDirectoryTokenProvider(
              async (audience, authority, state) => {
                  Console.WriteLine("Client ID: {0}", ClientId);
                  Console.WriteLine("Aud: {0}", audience);
                  IConfidentialClientApplication app = ConfidentialClientApplicationBuilder.Create(ClientId)
                    .WithAuthority(authority)
                    .WithClientSecret(ConfigurationManager.AppSettings["clientSecret"])
                    .Build();
                  Console.WriteLine("App: {0} ", app);

                  var authResult = await app.AcquireTokenForClient(new string[] {
              $"{audience}.default"
                  }).ExecuteAsync();
                  Console.WriteLine("Access Token: {0}", authResult.AccessToken);
                  return authResult.AccessToken;
              },
              $"https://login.microsoftonline.com/{TenantId}");

            var ehClient = EventHubClient.CreateWithTokenProvider(new Uri($"sb://{EventHubNamespace}/"), EventHubName, tp);
            Console.WriteLine("EH Client: {0}", ehClient.ClientId);
            return ehClient;
        }

        static async Task sendEvents(EventHubClient ehClient)
        {
            var clientStub = new claimInfo();
            clientStub.providerID = "provider1";
            clientStub.data1 = "some data";
            clientStub.patientId = "xxxyyy001";

            Console.WriteLine("Sending event");
            for (int i = 1; i <= numOfEvents; i++)
            {
                await ehClient.SendAsync(new EventData(Encoding.UTF8.GetBytes($"{clientStub}")));
            }
            Console.WriteLine("Send done");
            await receiveEvents(ehClient);
        }

        static async Task receiveEvents(EventHubClient ehClient)
        {
            Console.WriteLine("Fetching eventhub description to discover partitions");
            var ehDesc = await ehClient.GetRuntimeInformationAsync();
            Console.WriteLine("ehDesc {0}", ehDesc);
            Console.WriteLine($"Discovered partitions as {string.Join(", ", ehDesc.PartitionIds)}");

            var receiveTasks = ehDesc.PartitionIds.Select(async partitionId => {
                Console.WriteLine($"Initiating receiver on partition {partitionId}");
                var receiver = ehClient.CreateReceiver(PartitionReceiver.DefaultConsumerGroupName, partitionId, EventPosition.FromEnd());

                while (true)
                {
                    Console.WriteLine("Starting Loop");
                    Console.WriteLine("{0}", receiver.ClientId);
                    Console.WriteLine("{0}", receiver.ConsumerGroupName);
                    Console.WriteLine("{0}", receiver.EventHubClient);
                    Console.WriteLine("Part ID {0}", receiver.PartitionId);
                    var events = await receiver.ReceiveAsync(10, TimeSpan.FromSeconds(120));
                    Console.WriteLine("Event: {0}", events);
                    if (events == null)
                    {
                        Console.WriteLine("Ending Loop");
                        break;
                    }

                    var eventData = events.FirstOrDefault();
                    Console.WriteLine("Events: {0}", events);
                    foreach (EventData c in events)
                    {
                        Console.WriteLine("Data: {0}", Encoding.UTF8.GetString(c.Body.Array));
                    }
                    Console.WriteLine($"Received from partition {partitionId} with message content '" + Encoding.UTF8.GetString(eventData.Body.Array) + "'");
                }

                await receiver.CloseAsync();
            }).ToList<Task>();

            Console.WriteLine("Waiting for receivers to complete");
            await Task.WhenAll(receiveTasks);
            Console.WriteLine("All receivers completed");

            await ehClient.CloseAsync();
            
        }
    }
}

I have modified the sample from here: https://github.com/Azure/azure-event-hubs/blob/master/samples/DotNet/Microsoft.Azure.EventHubs/Rbac/AzureEventHubsSDK/Program.cs

The issue is on line 120 as events is always returned as null.

Am I missing something?