UICollectionViewCompositionalLayout unexpected behavior with .estimated heights

Using NSCollectionLayoutSize with .estimated dimensions in horizontal orthogonal sections, creates layout issues. The cells & supplementary views have layout conflicts, the scroll behavior is sub optimal and spacing is not as expected

Working with Xcode: 12.4 , Simulator: iOS 14.4
Layout bug:

Code Block 
[LayoutConstraints] Unable to simultaneously satisfy constraints.
	Probably at least one of the constraints in the following list is one you don't want. 
	Try this: 
		(1) look at each constraint and try to figure out which you don't expect; 
		(2) find the code that added the unwanted constraint or constraints and fix it. 
(
    "<NSLayoutConstraint:0x6000011266c0 UIView:0x7fc6c4617020.height == 80   (active)>",
    "<NSLayoutConstraint:0x600001126530 V:|-(0)-[UIView:0x7fc6c4617020]   (active, names: '|':UIView:0x7fc6c4616d10 )>",
    "<NSLayoutConstraint:0x6000011261c0 UIView:0x7fc6c4617020.bottom == UIView:0x7fc6c4616d10.bottom   (active)>",
    "<NSLayoutConstraint:0x600001121360 'UIView-Encapsulated-Layout-Height' UIView:0x7fc6c4616d10.height == 50   (active)>"
)
Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x6000011266c0 UIView:0x7fc6c4617020.height == 80   (active)>

Code to reproduce:

Code Block 
import UIKit
class ViewController: UIViewController {
  lazy var collectionView: UICollectionView = {
    let layout = createLayout()
    let collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)
    collectionView.translatesAutoresizingMaskIntoConstraints = false
    collectionView.dataSource = self
    collectionView.backgroundColor = .systemBackground
    collectionView.register(Cell.self, forCellWithReuseIdentifier: "cell")
    collectionView.register(HeaderView.self, forSupplementaryViewOfKind: UICollectionView.elementKindSectionHeader,
                            withReuseIdentifier: "header")
    return collectionView
  }()
  private func createLayout() -> UICollectionViewCompositionalLayout {
    let sectionProvider = { (section: Int,
                             layoutEnvironment: NSCollectionLayoutEnvironment) -> NSCollectionLayoutSection? in
      return self.horizontalLayout(layoutEnvironment: layoutEnvironment)
    }
    let config = UICollectionViewCompositionalLayoutConfiguration()
        config.interSectionSpacing = 8
    let layout = UICollectionViewCompositionalLayout(sectionProvider: sectionProvider, configuration: config)
    return layout
  }
  private func supplementaryHeader() -> NSCollectionLayoutBoundarySupplementaryItem {
    let titleSize = NSCollectionLayoutSize(widthDimension: .fractionalWidth(1.0), heightDimension: .estimated(50))
    let titleSupplementary = NSCollectionLayoutBoundarySupplementaryItem(
      layoutSize: titleSize,
      elementKind: UICollectionView.elementKindSectionHeader,
      alignment: .top)
    return titleSupplementary
  }
  private func horizontalLayout(layoutEnvironment: NSCollectionLayoutEnvironment) -> NSCollectionLayoutSection {
    let size = NSCollectionLayoutSize(widthDimension: .estimated(120), heightDimension: .estimated(50))
    let item = NSCollectionLayoutItem(layoutSize: size)
    let group = NSCollectionLayoutGroup.horizontal(layoutSize: size, subitems: [item])
    let section = NSCollectionLayoutSection(group: group)
    section.orthogonalScrollingBehavior = .continuous
    section.interGroupSpacing = 8
    section.contentInsets = NSDirectionalEdgeInsets(top: 16, leading: 16, bottom: 16, trailing: 16)
    section.boundarySupplementaryItems = [supplementaryHeader()]
    return section
  }
  override func viewDidLoad() {
    super.viewDidLoad()
    view.addSubview(collectionView)
    NSLayoutConstraint.activate([
      collectionView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
      collectionView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
      collectionView.topAnchor.constraint(equalTo: view.topAnchor),
      collectionView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
    ])
  }
}
// MARK: UICollectionViewDataSource
extension ViewController: UICollectionViewDataSource {
  func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
    let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath)
    return cell
  }
  func numberOfSections(in collectionView: UICollectionView) -> Int {
    return 25
  }
  func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
    return 4
  }
  func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String,
                      at indexPath: IndexPath) -> UICollectionReusableView {
    switch kind {
    case UICollectionView.elementKindSectionHeader:
      let header: HeaderView = collectionView.dequeueReusableSupplementaryView(ofKind: UICollectionView.elementKindSectionHeader,
                                                                               withReuseIdentifier: "header", for: indexPath) as! HeaderView
      return header
    default: fatalError()
    }
  }
}
class Cell: UICollectionViewCell {
  lazy var view: UIView = {
    let view = UIView()
    view.translatesAutoresizingMaskIntoConstraints = false
    view.backgroundColor = .systemRed
    return view
  }()
  override init(frame: CGRect) {
    super.init(frame: frame)
    configure()
  }
  required init?(coder: NSCoder) {
    fatalError("not implemented")
  }
  func configure() {
    contentView.addSubview(view)
    view.heightAnchor.constraint(equalToConstant: 80).isActive = true
    view.widthAnchor.constraint(equalToConstant: 100).isActive = true
    NSLayoutConstraint.activate([
      view.leadingAnchor.constraint(equalTo: contentView.leadingAnchor),
      view.trailingAnchor.constraint(equalTo: contentView.trailingAnchor),
      view.topAnchor.constraint(equalTo: contentView.topAnchor),
      view.bottomAnchor.constraint(equalTo: contentView.bottomAnchor)
    ])
  }
}
class HeaderView: UICollectionReusableView {
  lazy var view: UIView = {
    let view = UIView()
    view.translatesAutoresizingMaskIntoConstraints = false
    view.backgroundColor = .systemTeal
    return view
  }()
  override init(frame: CGRect) {
    super.init(frame: frame)
    configure()
  }
  required init?(coder: NSCoder) {
    fatalError("not implemented")
  }
  func configure() {
    addSubview(view)
    view.heightAnchor.constraint(equalToConstant: 60).isActive = true
    NSLayoutConstraint.activate([
      view.leadingAnchor.constraint(equalTo: self.leadingAnchor),
      view.trailingAnchor.constraint(equalTo: self.trailingAnchor),
      view.topAnchor.constraint(equalTo: self.topAnchor),
      view.bottomAnchor.constraint(equalTo: self.bottomAnchor)
    ])
  }
}