iOS 26 RC: Scope buttons never appear for integrated UISearchBar

When trying to use a UISearchController setup with a UISearchBar that has scope buttons, the search controller's scopeBarActivation property is set to .onSearchActivation, the navigation item's preferredSearchBarPlacement property is set to .integrated. or .integratedButton, and the search bar/button appears in the navigation bar, then the scope buttons never appear. But space is made for where they should appear.

Some relevant code in a UIViewController shown as the root view controller of a UINavigationController:

private func setupSearch() {
    let sc = UISearchController(searchResultsController: UIViewController())
    sc.delegate = self
    sc.obscuresBackgroundDuringPresentation = true

    // Setup search bar with scope buttons
    let bar = sc.searchBar
    bar.scopeButtonTitles = [ "One", "Two", "Three", "Four" ]
    bar.selectedScopeButtonIndex = 0
    bar.delegate = self

    // Apply the search controller to the nav bar
    navigationItem.searchController = sc

    // BUG - Under iOS/iPadOS 26 RC, using .onSearchActivation results in the scope buttons never appearing at all
    //       when using integrated placement in the nav bar.

    // Ensure the scope buttons appear immediately upon activating the search controller
    sc.scopeBarActivation = .onSearchActivation

    // This works but doesn't show the scope buttons until the user starts typing - that's too late for my needs
    //sc.scopeBarActivation = .automatic

    if #available(iOS 26.0, *) {
        // Under iOS 26 put the search icon in the nav bar - same issue for .integrated and .integratedButton
        navigationItem.preferredSearchBarPlacement = .integrated // .integratedButton
        // My toolbar is full so I need the search in the navigation bar
        navigationItem.searchBarPlacementAllowsToolbarIntegration = false // Ensure it's in the nav bar
    } else {
        // Under iOS 18 put the search bar in the nav bar below the title
        navigationItem.preferredSearchBarPlacement = .stacked
    }
}

I need the search bar in the navigation bar since the toolbar is full. And I need the scope buttons to appear immediately upon search activation.

This problem happens on any real or simulated iPhone or iPad running iOS/iPadOS 26 RC.