title: SwiftUI List with ForEach works in one VStack but not in second one
body: <p>I'm at a complete loss for why a List I'm trying to create (with a <code>ForEach</code>) in <code>SwiftUI</code> is behaving the way that it is. I have an <code>ObservedObject</code> that I verified in the inspector has the data that I'm expecting. In the first <code>VStack</code>, I can create the List with the <code>ForEach</code> and it outputs just fine. In the second <code>VStack</code>, I get no data output.</p>
  
  <pre><code>struct WorkoutPreview: View {
    @Environment(\.managedObjectContext) var managedObjectContext
    @ObservedObject var workoutSessionExercises: WorkoutSessionExercises
  
    var body: some View {
      NavigationView {
        VStack {
          Text("Welcome to your workout! Below are the exercises and bands you've selected for each.")
            .padding()
          Text("We found \(workoutSessionExercises.workoutExercises.count) workouts.")
            .padding()
  
          // This List (with ForEach) works fine and produces output.
          List {
            ForEach(0..&lt;workoutSessionExercises.workoutExercises.count) { index in
              Text(self.workoutSessionExercises.workoutExercises[index].exerciseName)
            }
          }
        }
  
        // The exact same List (with ForEach) in this VStack produces no results.
        VStack {
          List {
            ForEach(0..&lt;workoutSessionExercises.workoutExercises.count) { index in
              Text(self.workoutSessionExercises.workoutExercises[index].exerciseName)
            }
          }
        }
  
        Spacer()
      }
    }
  }
  </code></pre>