title: iOS Beta 5 SwiftUI List duplicates single item
body: <p>Has anyone else seen this in iOS 14 Beta 5? It worked fine in previous betas...</p>
  <pre><code>    @State private var favorites = [Truck]()
      @State private var favoritesRetreived = false
  
      var body: some View {
          List {
              ForEach(favorites, id:\.id) { truck in
                  NavigationLink (destination: TruckDetail(truck: truck)) {
                      TruckListItem(truck: truck)
                  }
              }
          }
          .navigationBarTitle(Text(&quot;Favorites&quot;), displayMode: .inline)
          .onAppear(perform: {
              getFavoriteTrucks()
          })
      }
  
  </code></pre>
  <p>The data in favorites is properly updated in the call to getFavoriteTrucks, but the list simply shows the first item duplicated for favorites.count number of times. I KNOW this was working correctly in previous betas... Did something change that I missed?</p>