Page stops rendering when Service using Messenger

[ciscisSC]

Hi.
Im quite new at x-platform development and need help solving a problem.
I have looked at the ToDoList app sampel and UNO page about Messenger and can't solve my problem.
I have a Service that should add a Tag to my db via an API and then update a list in the page that was used to add the Tag. The Service code looks like this:

public class SettingsService(DocumentHandlerAPIEndpoint Endpoints, IMessage Messenger)
{
   public async Task AddTagAsync(string name, CancellationToken ct)
   {
      try
      {
        var createdTag = await Endpoints.AddTag(new TagDTO { Name = name }, ct);

        var tag = new Tag(createdTag.Name);

        Messenger.Send(new EntityMessage<Tag>(EntityChange.Created, tag));
      }
      catch (Exception ex)
      {
         throw new Exception(ex.Message);
      }
   }
}

The IMessenger is from CommunityToolkit.Mvvm.Messaging and I have added Mvvm and MVUX to my .csproj file as instructed in the docs
However when I add the Service to my Model (using DI and the MVUX pattern) my page stops rendering all together.
Do I need to register the iMessage in my App.xaml.cs file? I can't se that it is done in the ToDoList app in the sampels.
I do not get any error when debugging.

The Message is the received .Observe method. If I comment out the IMessge part of the service file my page starts render again.

I have followed this guide:
https://platform.uno/docs/articles/external/uno.extensions/doc/Learn/Mvux/Advanced/Messaging.html#mvux-integration-with-the-messenger

[ciscisSC]

I had missed that I needed to register the IMessenger in app.xaml.cs. I thought that only was if I had a custom Messenger service. And the Sampel app had all there services registered in an other page.