Testing MudBlazor component always renders empty markup

Question

I want to make some tests for a modal component made in blazor with mudblazor.

Here's my component

ModalComplejo.razor

<MudDialog>
    <TitleContent>@Titulo</TitleContent>
    <DialogContent>
        @Contenido
    </DialogContent>
    <DialogActions>
        @Botonera
    </DialogActions>
</MudDialog>

@code {
    [Parameter, EditorRequired]
    public RenderFragment Titulo { get; set; } = default!;
    [Parameter, EditorRequired]
    public RenderFragment Contenido { get; set; } = default!;
    [Parameter, EditorRequired]
    public RenderFragment Botonera { get; set; } = default!;
}

ModalComplejoTests.razor

@code {

    [Fact]
    public void RenderModalComplejo()
    {
        Services.AddSingleton<MudDialogProvider>();
        Services.AddSingleton<IDialogService, DialogService>();

        var cut = Render(
    @<ModalComplejo>
        <Titulo>
            <h1>Caso 1122</h1>
        </Titulo>
        <Contenido>
            <h2>Lorem ipsum</h2>
            <p>Lorem ipsum factum...</p>
        </Contenido>
        <Botonera>
            <label for="guardar-btn">Guardar</label>
            <input type="button" id="guardar-btn" />
            <label for="cerrar-btn">Cerrar</label>
            <input type="button" id="cerrar-btn" />
        </Botonera>
        </ModalComplejo>
    );
      cut.MarkupMatches("<H1>Hello World<H1>");

     //   var ds = new DialogService();
     //   ds.Show<ModalComplejo>()
    }
}

As you can see, I'm using a templated razor delegate to define de test. I debugged it and the markup always return empty.

I think this has to do with the fact that the modal is never triggered. I should open it first and then the markup will appear, but I don't have an idea how to accomplish that, any ideas how to fix this? or maybe it is another issue that I'm not seeing.