How to disable Blazor server side pre-render?

To disable server side pre-render on asp.net core preview 3, you just needed to comment @(await Html.RenderComponentAsync<MyApp>()).

Since asp.net core preview 4, when you comment this line, the page doesn't render and on the main component @page "/", the tag <app> remains blank.

So, how can we disable server side pre-render ?