`setCollectionViewLayout` crash on iOS 14.2 but works well on other systems - ios

Question

When I hit the button in iOS 14.2 , it will crash and the console will print the following message:
libc++abi.dylib: terminating with uncaught exception of type NSException
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[__NSDictionaryM setObject:forKey:]: object cannot be nil (key: <NSIndexPath: 0xb53fd3951e2cb315> {length = 2, path = 0 - 0})'
terminating with uncaught exception of type NSException
But it works well on other Systems.
here's the code:
import UIKit
enum DeviceListStyle: String {
case list
case flow
}
class ViewController: UIViewController {
var style: DeviceListStyle = .list
private lazy var flowLayout: UICollectionViewFlowLayout = {
let sizeW = (UIScreen.main.bounds.width - 45) / 2
let sizeH = sizeW * 120 / 165
let flowLayout = UICollectionViewFlowLayout()
flowLayout.itemSize = CGSize(width: sizeW, height: sizeH)
flowLayout.minimumLineSpacing = 15
flowLayout.minimumInteritemSpacing = 15
flowLayout.headerReferenceSize = CGSize(width: UIScreen.main.bounds.width - 30, height: 15)
flowLayout.footerReferenceSize = CGSize(width: UIScreen.main.bounds.width - 30, height: 15)
flowLayout.sectionInset.bottom = 15
return flowLayout
}()
private lazy var listLayout: UICollectionViewFlowLayout = {
let sizeW = UIScreen.main.bounds.width - 30
let sizeH: CGFloat = 70
let flowLayout = UICollectionViewFlowLayout()
flowLayout.itemSize = CGSize(width: sizeW, height: sizeH)
flowLayout.minimumLineSpacing = 10
flowLayout.minimumInteritemSpacing = 15
flowLayout.headerReferenceSize = CGSize(width: UIScreen.main.bounds.width - 30, height: 15)
flowLayout.footerReferenceSize = CGSize(width: UIScreen.main.bounds.width - 30, height: 15)
flowLayout.sectionInset.bottom = 15
return flowLayout
}()
lazy var collectionView: UICollectionView = {
let layout: UICollectionViewLayout
switch style {
case .list:
layout = listLayout
case .flow:
layout = flowLayout
}
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.backgroundColor = .clear
cv.delegate = self
cv.dataSource = self
cv.showsHorizontalScrollIndicator = false
cv.showsVerticalScrollIndicator = false
cv.alwaysBounceVertical = true
cv.alwaysBounceHorizontal = false
cv.register(UICollectionViewCell.self, forCellWithReuseIdentifier: "cell")
return cv
}()
lazy var btn: UIButton = {
let btn = UIButton()
btn.center = view.center
btn.frame.size = CGSize(width: 80, height: 50)
btn.titleLabel?.textAlignment = .center
btn.backgroundColor = .black
btn.setTitle("change", for: .normal)
btn.addTarget(self, action: #selector(switchStyle), for: .touchUpInside)
return btn
}()
#objc private func switchStyle() {
switch style {
case .list:
self.collectionView.setCollectionViewLayout(self.flowLayout, animated: true) { [weak self] _ in
guard let self = self else { return }
self.collectionView.reloadItems(at: self.collectionView.indexPathsForVisibleItems)
}
self.style = .flow
case .flow:
self.collectionView.setCollectionViewLayout(self.listLayout, animated: true) { [weak self] _ in
guard let self = self else { return }
self.collectionView.reloadItems(at: self.collectionView.indexPathsForVisibleItems)
}
self.style = .list
}
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
collectionView.backgroundColor = .purple
collectionView.frame = view.bounds
view.addSubview(collectionView)
view.addSubview(btn)
}
}
extension ViewController: UICollectionViewDelegate, UICollectionViewDataSource {
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return 1
}
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "cell", for: indexPath)
return cell
}
}