Combining a TabView with PageTabViewStyle, a NavigationView and a ScrollView correctly in SwiftUI

I am working on a UI that combines a TabView with PageTabViewStyle, a NavigationView and a ScrollView. When scrolling down, I expect the title of the NavigationView to adjust and get smaller. But it does not when the ScrollView is placed inside the TabView. How do I implement this behavior?

This is an extension to my original question on how to use a TabView with PageTabViewStyle and a NavigationView together.

struct ContentView: View {
    @State var selection = 1
    
    var body: some View {
        NavigationView {
            TabView {
                LibraryView()
                    .tag(1)
                LibraryView()
                    .tag(2)
            }
            .navigationTitle(selection == 1 ? "A" : "B")
        }
        .tabViewStyle(PageTabViewStyle(indexDisplayMode: .never))
        //.indexViewStyle(PageIndexViewStyle(backgroundDisplayMode: .always))
    }
}

struct LibraryView: View {
    
    @State var gridLayout: [GridItem] = [
        GridItem(),
        GridItem()
    ]
    
    var body: some View {
        ScrollView {
            LazyVGrid(columns: gridLayout, alignment: .center, spacing: 10) {
                ForEach(collections.indices) { index in
                    CollectionItem(collection: collections[index])
                }
            }
            .padding(.all, 10)
        }
    }
}