Open Radar

 
Summary:
Just pushed via NavigationLink view gets popped out.

Steps to reproduce:
1. Create SwiftUI iOS app with following implementation
```
import SwiftUI

@main
struct PopBug1App: App {
    var body: some Scene {
        WindowGroup {
            FirstView()
        }
    }
}

struct FirstView: View {
    var body: some View {
        NavigationView {
            NavigationLink(destination: SecondView()) {
                Text("Second view")
            }
        }
    }
}

struct SecondView: View {
    @Environment(\.presentationMode) var presentationMode
    @StateObject var viewModel = SecondViewModel()

    var body: some View {
        VStack(spacing: 8) {
            NavigationLink(destination: Text("Details"), isActive: $viewModel.detailsVisible) {
                EmptyView()
            }

            NavigationLink(destination: Text("About")) {
                Text("About")
            }

            Button("Details") {
                viewModel.detailsVisible = true
            }
        }
    }
}

class SecondViewModel: ObservableObject {
    @Published var detailsVisible: Bool = false
}
```
2. Run the app
3. Navigate to second screen by tapping 'Second view' button
4. Tap on 'About' or 'Details' button

Observed behavior:
New screen gets pushed and immediately popped.

Expected behavior:
User stays on pushed screen

Note:
Believe issue was introduced in iOS 14.5, because I can’t reproduce it on previous versions.
Changing view hierarchy by adding another NavigationLink fixes the issue.

Versions:
Xcode 12.5 (12E262)
iOS 14.5.1 (18E212)
macOS 11.2.3 (20D91)