This is most probably a result of some CSS adding margin or max-width that centers the content container within the browser window, making the content look indented. You can use DevTools to inspect the element in the browser and see what is causing it.
The RadzenBody.razor.cs seems to be applying a 250px left margin if the layout is null, but as far as I can tell my layout is not null since my page is assigned to a layout.
For now I am applying -250px margin to offset this. Are you able to reproduce this or is this expected behavior?