title: SwiftUI list animations looks strange
body: <p>my SwiftUI animations for a list looks strange:
  <a href="https://i.stack.imgur.com/UYVxI.gif" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/UYVxI.gif" alt="enter image description here" /></a></p>
  <p>I use nearly the default border plate code from the CoreData starter project in Xcode 12.5:</p>
  <pre><code>struct ListView: View {
      @Environment(\.managedObjectContext) private var viewContext
      
      @FetchRequest(
          sortDescriptors: [NSSortDescriptor(keyPath: \Item.date, ascending: true)])
      private var items: FetchedResults&lt;Item&gt;
      
      @State private var isShowingScanner = false
      
      var body: some View {
          NavigationView {
              List {
                  ForEach(items) { item in
                      Text(&quot;Item at \(item.timestamp, formatter: itemFormatter)&quot;)
                  }
                  .onDelete(perform: deleteItems)
              }
              .navigationTitle(&quot;List&quot;)
              .toolbar {
                  ToolbarItemGroup(placement: .navigationBarTrailing) {
                      EditButton()
                      // ...                    
                  }
                  
              }
          }
      }
  
      private func deleteItems(offsets: IndexSet) {
          //...
      }
  }
  </code></pre>
  <p>Any hint why this is happening?</p>