Prism Dialog: Unable to resolve Resolution root Object

I tried this with Prism 8.0.0.1909 and dotnet core 3.1 and 5. For my dialog I have a view:

<UserControl
x:Class="xzy.Modules.CapillaryBatchwise.Dialogs.NewBatchDialog"
xmlns:prism="http://prismlibrary.com/"
prism:ViewModelLocator.AutoWireViewModel="True">
...
</UserControl>

and a View Model with nothing really in it for now:

namespace zxy.Modules.CapillaryBatchwise.ViewModels
{
public class NewBatchDialogViewModel : BindableBase, IDialogAware
    {
        ...
        public string Title => "MyTitle";
        public event Action<IDialogResult> RequestClose;
        public bool CanCloseDialog() => true;

        public void OnDialogClosed()
        { }

        public void OnDialogOpened(IDialogParameters parameters)
        { }
    }
}

I registered the View and View Model in my App.xaml.cs

namespace xyz.CapillaryJournal
{
    public partial class App
    {
        ...
        protected override void RegisterTypes(IContainerRegistry containerRegistry)
        {
            containerRegistry.RegisterDialog<NewBatchDialog, NewBatchDialogViewModel>();
        }
}}

And then call it from my actual ViewModel

 public class CapillaryBatchNavigationViewModel : BindableBase
    {
        private readonly IDialogService dialogService;

        public CapillaryBatchNavigationViewModel(//...
                                                 IDialogService dialogService)
        {
            ///...
            ShowNewBatchDialogCommand = new DelegateCommand(ShowNewBatchDialog);
            this.dialogService = dialogService;
            //...
        }
        public DelegateCommand ShowNewBatchDialogCommand { get; }
        private void ShowNewBatchDialog()
        {
            dialogService.ShowDialog(nameof(ShowNewBatchDialog));
        }
        //...
    }

However when I call ShowNewBatchDialogCommand from my View I get this exception, that I can't make any sense of:

Prism.Ioc.ContainerResolutionException: 'An unexpected error occurred while resolving 'System.Object', with the service name 'ShowNewBatchDialog''

Inner Exception
ContainerException: code: Error.UnableToResolveFromRegisteredServices;
message: Unable to resolve Resolution root Object {ServiceKey="ShowNewBatchDialog"}
  from container without scope
 with Rules with {TrackingDisposableTransients, UseDynamicRegistrationsAsFallbackOnly, FuncAndLazyWithoutRegistration, SelectLastRegisteredFactory} and without {ThrowOnRegisteringDisposableTransient, UseFastExpressionCompilerIfPlatformSupported}
 with FactorySelector=SelectLastRegisteredFactory
 with Made={FactoryMethod=ConstructorWithResolvableArguments}
  with normal and dynamic registrations:
  ("NewBatchDialog", {FactoryID=160, ImplType=xyy.Modules.CapillaryBatchweise.Dialogs.NewBatchDialog, Reuse=TransientReuse})  ("TaskPresenter", {FactoryID=177, ImplType=xyy.Modules.CapillaryBatchweise.Views.TaskPresenter, Reuse=TransientReuse})

This is basically slightly modified what was done in this doc: https://prismlibrary.com/docs/wpf/dialog-service.html

I can't spot what is wrong with my code.