An extra UITableViewCellContentView overlay appears in a TableView on iOS 14 preventing taps, but works fine on iOS 13

You have to add your views to cell contentView like this:

contentView.addSubview(button)

and anchor your button to contentView:

button.topAnchor.constraint(equalTo: contentView.topAnchor).isActive = true

If your project is big and it's hard to change every addSubview to contentView.addSubview, you can add this extension to your project:

extension UITableViewCell {
    open override func addSubview(_ view: UIView) {
        super.addSubview(view)
        sendSubviewToBack(contentView)
    }
}