We have a singleton service which subscribes to PublishedContent and MovedContent from IContentEvents. And this works as expected locally, when the CMS is running in a single IIS application. When the app is deployed in multiple load balanced IIS applications, we use EPiServer.Azure, which works as expected for propagating changes from CMS like publishing of new pages to every instance. But we are not getting any published or moved content events in the singleton service in this envirnoment. 

example from Startup.cs

public void ConfigureServices(IServiceCollection services)
{
    ...
    services.AddCms();
    ...
    services.AddSignleton<MyService>();
    ...
    services.AddAzureEventProvider(o =>
    {
        o.ConnectionString = _configuration.GetValue<string>("AzureEventBus:ConnectionString");
        o.TopicName = _configuration.GetValue<string>("AzureEventBus:Topic");
        o.EnablePartitioning = false;
        o.TopicSize = 1024; // 1GB
    });
...

from MyService.cs

public class MyService {
  public NavigationBuilder(IContentEvents contentEvents) {
     contentEvents.PublishedContent += OnContentUpdated;
     contentEvents.MovedContent += OnContentUpdated;
  }

  private void OnContentUpdated(object sender, ContentEventArgs e)
  {
     // do something; gets called on local; never called in load balanced env
  }
}