title: Azure Service Bus trigger not firing sometimes
body: <p>I created function app v1 with one function in it. The function is a service bus trigger.</p>
  
  <p>After publishing it to Azure i see this strange behaviour.
  Sometimes the function gets triggered and sometimes it's not. There are no errors in logs at that time, but i see messages were put into dead letter queue with "delivery count excided" error.</p>
  
  <p>Now, if i try to resend failed messages - it fails again. But if i go to portal, refresh function app and send the messages again - they get picked up and processed as usual.</p>
  
  <p>Here's how i send messages:</p>
  
  <pre><code>var client = new QueueClient(connectionString, queueName);
  var bytes = Encoding.UTF8.GetBytes(msgStr);
  var message = new Message(bytes);
  await queueClient.SendAsync(message);
  </code></pre>
  
  <ul>
  <li>I don't see this issue when run function locally.</li>
  <li>New messages (&lt;5) arrive every 15-20 minutes</li>
  <li>I'm using  Consumption plan </li>
  <li>host.json is empty</li>
  </ul>
  
  <p>Please help.</p>