Collection view does not show any item after flashing

I'm facing this weird problem with UICollectionView. I created a custom view controller which contain a UICollectionView by xib file. Then I add the custom view controller to the main view and fill data for the collection view after added. But every time the view is shown, the collection view flashes and then it show blank, no item?! It's really really weird, I've never seen it before?! You can see it in the video below: https://youtu.be/Pwn8cufpQ1Y Here's how I add the custom view: let list = HorizontalListViewController(nibName: "HorizontalListViewController", bundle: nil) list.view.translatesAutoresizingMaskIntoConstraints = false self.contentView.addSubview(list.view) let constraintTop = NSLayoutConstraint(item: list.view, attribute: .Top, relatedBy: .Equal, toItem: self.contentView, attribute: .Top, multiplier: 1, constant: self.contentViewHeight.constant) let constraintLead = NSLayoutConstraint(item: list.view, attribute: .Leading, relatedBy: .Equal, toItem: self.contentView, attribute: .Leading, multiplier: 1, constant: 0) let constraintTrail = NSLayoutConstraint(item: list.view, attribute: .Trailing, relatedBy: .Equal, toItem: self.contentView, attribute: .Trailing, multiplier: 1, constant: 0) let constraintHeight = NSLayoutConstraint(item: list.view, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1, constant: CGFloat(LIST_VIEW_HEIGHT)) list.view.addConstraint(constraintHeight) self.contentView.addConstraints([constraintTop, constraintLead, constraintTrail]) list.setList(datas, title: title) Register the cell in viewDidLoad: // Do any additional setup after loading the view. self.collectionView.dataSource = self self.collectionView.delegate = self self.collectionView.registerNib(UINib(nibName:"HorizontalListCollectionViewCell", bundle: nil), forCellWithReuseIdentifier: CELL_IDENTIFIER) Did you see this problem before? How can I solve it? EDIT 1: I tried the solution which given by Santosh but the result is still the same, but now the cell show up a little bit longer before disappearing. Here's the video: https://youtu.be/8H4KqY6JJNs EDIT 2: I tried to create the custom view controller by using storyboard, but cells still keep disappearing