Почему не происходит transition у UISearchController`а?

class CompilationViewController: UIViewController, UISearchBarDelegate, UISearchControllerDelegate, UISearchResultsUpdating {
// ...
private var lastContentOffset: CGFloat = 0
private var isVisible = true
private var constraints = [NSLayoutConstraint]()

@IBOutlet var collection: UICollectionView!
@IBOutlet var logo: UIImageView!
@IBOutlet var segmentControl: UISegmentedControl!
private var searchController: UISearchController!
private var searchView: UIView!



override func loadView() {
    super.loadView()

    for item in view.subviews {
        item.translatesAutoresizingMaskIntoConstraints = false
    }

    searchController = UISearchController(searchResultsController: nil)
    searchController.searchResultsUpdater = self
    searchController.obscuresBackgroundDuringPresentation = false
    searchController.searchBar.delegate = self
    searchController.searchBar.searchBarStyle = .minimal

    searchView = UIView()
    searchView.addSubview(searchController.searchBar)
    //searchController.searchBar.sizeToFit()

    view.addSubview(searchView)
    searchView.translatesAutoresizingMaskIntoConstraints = false

    constraints.append(logo.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor))
    constraints[0].isActive = true
    logo.widthAnchor.constraint(equalToConstant: 160).isActive = true
    logo.heightAnchor.constraint(equalToConstant: 38).isActive = true
    logo.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true

    constraints.append(segmentControl.topAnchor.constraintEqualToSystemSpacingBelow(logo.bottomAnchor, multiplier: 1))
    constraints[1].isActive = true
    segmentControl.widthAnchor.constraint(equalTo: view.safeAreaLayoutGuide.widthAnchor, multiplier: 1, constant: -16).isActive = true
    segmentControl.centerXAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerXAnchor).isActive = true

    constraints.append(searchView.topAnchor.constraintEqualToSystemSpacingBelow(segmentControl.bottomAnchor, multiplier: 1))
    constraints[2].isActive = true
    searchView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
    searchView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
    searchView.heightAnchor.constraint(equalToConstant: 56).isActive = true

    constraints.append(collection.topAnchor.constraintEqualToSystemSpacingBelow(searchView.bottomAnchor, multiplier: 1))
    constraints[3].isActive = true
    collection.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor).isActive = true
    collection.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor).isActive = true
    collection.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
}

override func viewDidLoad() {
    super.viewDidLoad()
}