iOS14 Widgetkit widgetfamily only medium!!

I am using xcode Version 12.1

Widgets are added by size to the app being serviced, but only the medium size is shown.
Below is the code.

var entry: Provider.Entry
  @Environment(\.widgetFamily) var family
  var body: some View {
    VStack {
      Text(entry.date, style: .time)
      switch family {
      case .systemSmall:
        Text("Small")
      case .systemMedium:
        Text("Medium")
      case .systemLarge:
        Text("Large")
      default:
        Text("Some other WidgetFamily in the future.")
      }
    }
  }

and It works well when it comes to a new project, but why does this work in an existing app?