Hi @Taihao,
For some reason the app does not stretch to 100% height. You can try setting <RadzenLayout class="rz-h-100">. Also, is the theme loaded? The buttons in the screenshot don't look like the default Radzen Material buttons, so the theme styles might be missing. Perhaps this thread could help -> How can I set up material light and dark mode in a MAUI or Blazor standalone app? - #7 by Igor