If you're using MVC, please register "Area ControllerRoute" and "Default ControllerRoute" before app.UseI18nDashboard().
For example:
var app = builder.Build();
// Additional middlewares
app.MapControllerRoute(
name: "area",
pattern: "{area:exists}/{controller=Home}/{action=Index}/{id?}");
app.MapControllerRoute(
name: "default",
pattern: "{controller=Home}/{action=Index}/{id?}");
if (app.Environment.IsDevelopment())
{
app.UseI18nDashboard();
}
app.MapRazorPages();
app.Run();