Swift 3 Button in UICollectionViewCell not respond to touch

I have an UICollectionViewCell and two buttons inside that, but the buttons not respond to touch, i create button programmatically and add that to cell by addSubView it works, but when i added by holder.addSubView not working!

UserInteractionEnabeld of holder is true!

help please

class FavoriteProductCollectionViewCell: UICollectionViewCell {

    @IBOutlet weak var holder: UIView!


    override func awakeFromNib() {
        super.awakeFromNib()

        let btnFindBestPrice = UIButton(frame: CGRect(x: 0, y: 0, width: 151, height: 20))



        btnFindBestPrice.setTitle("Find best price", for: .normal)
        btnFindBestPrice.backgroundColor = UIColor.ButtonBackGreen

        btnFindBestPrice.isUserInteractionEnabled = true

        btnFindBestPrice.addTarget(self, action: #selector(findBestPrice), for: .touchUpInside)

        // AddTarget not working
        holder.addSubview(btnFindBestPrice)


        // AddTarget works fine
        addSubview(btnFindBestPrice)
    }
}

Swift 3 Button in UICollectionViewCell not respond to touch