UITableViewのスクロール時にUITableViewCellの状態を維持するにはどうすればよいですか？

UITableViewCellの拡張について質問があります。
「もっと見る」というタイトルのUIButtonをクリックすると、正常に展開されます。
次に、UITableViewをスクロールすると、クリックしていないもう1つのセルである状況が表示されます。UIButtonも展開されます。
この問題を解決するための良いアイデアはありますか？
ありがとう。

class ViewController: UIViewController {

let tableView = UITableView()
let cellWithButton = "cellWithButton"
var isExpand: Bool = false
var expandIndexs: [IndexPath] = []
let text = "If you read and listen to two articles every day, your reading and listening skills can immm If you read and listen to two articles every day, your reading and listening skills can immm If you read and listen to two articles every day, your reading and listening skills can immm If you read and listen to two articles every day, your reading and listening skills can immm If you read and listen to two articles every day, your reading and listening skills can immm"

override func viewDidLoad() {
    super.viewDidLoad()

    tableView.delegate = self
    tableView.dataSource = self
    tableView.allowsSelection = false
    tableView.separatorInset = .zero
    tableView.estimatedRowHeight = 44
    tableView.rowHeight = UITableViewAutomaticDimension
    tableView.register(WithButtonTableViewCell.self, forCellReuseIdentifier: cellWithButton)


    self.view.addSubview(tableView)

    tableView.snp.makeConstraints { (make) in
        make.top.left.right.bottom.equalToSuperview()
    }
}

@objc func btnPressed(sender: UIButton) {

    let indexPath = IndexPath(row: sender.tag, section: 0)

    if self.isExpand == false {

        self.isExpand = true

        self.expandIndexs.append(indexPath)

    } else {
        self.isExpand = false

        let index = self.expandIndexs.index(of: indexPath)

        if let index = index {
            self.expandIndexs.remove(at: index)
        }
    }

    tableView.beginUpdates()
    tableView.reloadRows(at: [indexPath], with: .none)
    tableView.endUpdates()

}
}

extension ViewController: UITableViewDelegate, UITableViewDataSource {

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return 10
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {

    let cell = tableView.dequeueReusableCell(withIdentifier: cellWithButton, for: indexPath) as! WithButtonTableViewCell

    if self.expandIndexs.contains(indexPath) {
        cell.cellIsExpand = self.isExpand
    }
    cell.titleLabel.text = text
    cell.expandButton.addTarget(self, action: #selector(btnPressed), for: .touchUpInside)
    cell.expandButton.tag = indexPath.row
    cell.layoutIfNeeded()

    return cell
}
}


class WithButtonTableViewCell: UITableViewCell {

var cellIsExpand: Bool = false

let titleLabel: UILabel = { () -> UILabel in
    let ui = UILabel()
    ui.textColor = UIColor.black
    return ui
}()

let expandButton: UIButton = { () -> UIButton in
    let ui = UIButton()
    ui.setTitleColor(UIColor.blue, for: .normal)
    return ui
}()

override func awakeFromNib() {
    super.awakeFromNib()
    // Initialization code
}

override func setSelected(_ selected: Bool, animated: Bool) {
    super.setSelected(selected, animated: animated)

    // Configure the view for the selected state
}

override init(style: UITableViewCellStyle, reuseIdentifier: String?) {
    super.init(style: style, reuseIdentifier: reuseIdentifier)

    loadUI()
    loadLayout()
}

required init?(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")

}

override func layoutIfNeeded() {
    super.layoutIfNeeded()

    if cellIsExpand == true {
        titleLabel.numberOfLines = 0
        expandButton.setTitle("Close.", for: .normal)
    }else{
        titleLabel.numberOfLines = 2
        expandButton.setTitle("Show More.", for: .normal)
    }
}

func loadUI() {

    self.addSubview(titleLabel)
    self.addSubview(expandButton)
}

func loadLayout() {

    titleLabel.snp.makeConstraints { (make) in
        make.top.left.equalTo(15)
        make.right.equalTo(-15)
    }

    expandButton.snp.makeConstraints { (make) in
        make.top.equalTo(titleLabel.snp.bottom).offset(10)
        make.left.equalTo(10)
        make.right.equalTo(-15)
        make.bottom.equalTo(-15)            
    }
}
}