I have four models: Vegetables, Fruits, Herbs and Condiments. Each model has separate collection view, and different cell identifier. Data is successfully fetched which I confirmed by printing number of objects.

I have used DiffableDataSource, where data source is initialized as follows:

Data Source & snapshot:

var dataSource: UICollectionViewDiffableDataSource<String, NSManagedObjectID>?
typealias DataSource = UICollectionViewDiffableDataSource<String, NSManagedObjectID>
typealias Snapshot = NSDiffableDataSourceSnapshot<String, NSManagedObjectID>

Setting up data source:`

private func setupDataSource<T:NSManagedObject>(for collectionView:UICollectionView,
                                    with identifier: String,
                                    of entity: T.Type)
                                    ->DataSource
    {

         let dataSource = DataSource(
            collectionView: collectionView,
            cellProvider: {(collectionView, indexPath, managedObjectID) -> UICollectionViewCell? in

          let cell = collectionView.dequeueReusableCell(withReuseIdentifier: identifier, for: indexPath) as! KitchenCollectionViewCell

        if let pantry = try? self.kitchenCoreDataStack.managedContext.existingObject(with: managedObjectID) as? T {
          self.configure(cell: cell, for: pantry)
        }
        return cell
})
         return dataSource
    }

When breakpoint is set in above code, it doesn't go past this line:

cellProvider: {(collectionView, indexPath, manageObjectID)

Snapshot code to reflect changes: extension KitchenViewController: NSFetchedResultsControllerDelegate{

func applySnapshot(animatingDifferences: Bool){
    let snapshot = Snapshot()
    dataSource?.apply(snapshot, animatingDifferences: animatingDifferences)
}

Thank you.