i have a Problem with my UICollectionView inside my Swift Xcode Project I checked all insets and margins, I tried the ViewController's: "Adjust Scroll View Insets" and lots of other stuff, but none of them did change this in any way.

i want to reduce / remove that top spacing above the first row of cells in my collectionView

I created a sample project to find a solution/fix for this issue, but didn't had any luck yet

This seems to be a issue when using a Collection View inserted via Storyboard /Interface builder, because this does not happen if I add the collectionView on the code side

Here's my View Controller's Code:

import UIKit

struct CVData: Hashable {
    var name: String
    var value: String
}

class ViewController: UIViewController {
    
    @IBOutlet weak var myCollectionView: UICollectionView!
    var dataSource: UICollectionViewDiffableDataSource<Section, CVData>!
    var cvDataList: [CVData] = []
    enum Section {
        case main
    }
    var CVDataLabels: [String] = ["Label1:","Label2:","Label3:","Label4:","Label5:","Label6:","Label7:","Label8:"]
    var CVDataValues: [String] = []
    var snapshot: NSDiffableDataSourceSnapshot<Section, CVData>!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        configureCollectionView()
        buildData()
        // Do any additional setup after loading the view.
    }

    func configureCollectionView() {
        
        let layoutConfig = UICollectionLayoutListConfiguration(appearance: .insetGrouped)
        let listLayout = UICollectionViewCompositionalLayout.list(using: layoutConfig)
        myCollectionView.collectionViewLayout = listLayout
        myCollectionView.isScrollEnabled = false
        let cellRegistration = UICollectionView.CellRegistration<UICollectionViewListCell, CVData> { (cell, indexPath, item) in

            var content = UIListContentConfiguration.cell()
            content.text = item.name
            content.textProperties.font.withSize(8.0)
            content.textProperties.font = UIFont.preferredFont(forTextStyle: .body)
            content.secondaryText = item.value
            content.prefersSideBySideTextAndSecondaryText = true
            content.textProperties.adjustsFontSizeToFitWidth = false
            cell.contentConfiguration = content
        }
        
        dataSource = UICollectionViewDiffableDataSource<Section, CVData>(collectionView: myCollectionView) {
            (collectionView: UICollectionView, indexPath: IndexPath, identifier: CVData) -> UICollectionViewCell? in
            
            // Dequeue reusable cell using cell registration (Reuse identifier no longer needed)
            let cell = collectionView.dequeueConfiguredReusableCell(using: cellRegistration,
                                                                    for: indexPath,
                                                                    item: identifier)
            // Configure cell appearance
            cell.accessories = [.disclosureIndicator()]
            
            return cell
        
    }
    }


    func buildData() {
        
        let cvDataList = [
            CVData(name: self.CVDataLabels[0], value: "value1"),
            CVData(name: self.CVDataLabels[1], value: "value2"),
            CVData(name: self.CVDataLabels[2], value: "value3"),
            CVData(name: self.CVDataLabels[3], value: "value4"),
            CVData(name: self.CVDataLabels[4], value: "value5"),
            CVData(name: self.CVDataLabels[5], value: "value6"),
            CVData(name: self.CVDataLabels[6], value: "value6"), //added 20210510
            CVData(name: self.CVDataLabels[7], value: "value7")
        ]
        
        // Create a snapshot that define the current state of data source's data
        self.snapshot = NSDiffableDataSourceSnapshot<Section, CVData>()
        self.snapshot.appendSections([.main])
        self.snapshot.appendItems(cvDataList, toSection: .main)

        // Display data in the collection view by applying the snapshot to data source
        self.dataSource.apply(self.snapshot, animatingDifferences: false)
    }
}

Here's the Size inspector settings from that UICOllectionView

Any help'd be greatly appreciated