I've checked iOS 18.1 beta as well. It's problem there as well. @sunwukongTH We had same problem in our project, this how we were able to solve it: override func collectionView(_ collectionView: UICollectionView, willDisplaySupplementaryView view: UICollectionReusableView, forElementKind elementKind: String, at indexPath: IndexPath) { guard elementKind == "customBackgroundElementKind" else { return } // Custom logic for setting background color let backgroundView = view as? BackgroundSection backgroundView?.setColor(.red) // actual workaround if #available(iOS 18.0, *) { backgroundView?.layer.zPosition = -5 } }