SwiftUI Section Header Not Pinned

I'm attempting to keep a section header on the screen when scrolling through a list but my code is not working. I'm following this Apple tutorial but my code has no effect on the header staying on the screen.

    var body: some View {
        NavigationSplitView {
            List {
                LazyVStack(pinnedViews: .sectionHeaders) {
                    ForEach(searchDates, id: \.self) { date in
                        Section(header: Text(date)) {
                            ReceiptSection(searchResults: searchResults, date: date)
                        }
                    }.onDelete(perform: deleteItems)
                }
            }

I have tried moving around where I insert the LazyVStack but that has no effect either. Can anyone tell me how to fix it?

Lazy stacks should be inside ScrollViews, not Lists. In fact, they are not "lazy" unless they are in a ScrollView. On the other hand, the List will treat it as one giant list row.

ScrollView {
    LazyVStack(pinnedViews: .sectionHeaders) {
        ForEach(searchDates, id: \.self) { date in
            Section(header: Text(date)) {
                ReceiptSection(searchResults: searchResults, date: date)
            }
        }.onDelete(perform: deleteItems)
    }
}

You can also consider using a ListStyle that has sticky headers. e.g. the .plain style on iOS. NavigationSplitView is designed to be driven by the selection of a List - it navigates to the detail view when a list row is selected.