UICollectionView doesn't scroll to bottom

I have an UICollectionView built programatically that doesn’t allow me to scroll to the last item in it.

Here is how I set it up

private let collectionView: UICollectionView = UICollectionView(
        frame: .zero,
        collectionViewLayout: UICollectionViewCompositionalLayout { sectionIndex, _ -> NSCollectionLayoutSection? in
            return WorkoutListViewController.createSectionLayout(section: sectionIndex)
        })

private static func createSectionLayout(section: Int) -> NSCollectionLayoutSection {
        // item
        let item = NSCollectionLayoutItem(
            layoutSize: NSCollectionLayoutSize(
                widthDimension: .fractionalWidth(1.0),
                heightDimension: .fractionalHeight(1.0)
            )
        )
        item.contentInsets = NSDirectionalEdgeInsets(top: 14, leading: 0, bottom: 14, trailing: 0)
        
        // group
        let verticalGroup = NSCollectionLayoutGroup.vertical(
            layoutSize: NSCollectionLayoutSize(
                widthDimension: .fractionalWidth(1.0),
                heightDimension: .absolute(123)
            ),
            repeatingSubitem: item,
            count: 1
        )
        
        // section
        let section = NSCollectionLayoutSection(group: verticalGroup)
        return section
    }

private func configureCollectionView() {
        view.addSubview(collectionView)
        
        collectionView.register(
            WorkoutListCollectionViewCell.self,
            forCellWithReuseIdentifier: WorkoutListCollectionViewCell.identifier
        )
        collectionView.delegate = self
        collectionView.dataSource = self
        collectionView.backgroundColor = .systemBackground
    }

I tried modifying the height by giving it a very large number (e.g 2000) and nothing changed. I also tried adding the UICollectionViewDelegateFlowLayout protocol to add the

func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
        
    }

function and return the CGSize of my item.

>Solution :

It seems your collection view is hiding behind the TabBar, So try to set the ContentInset of your collection view based on the bottom TabBar height.

Example:

collectionView.contentInset = .init(top: 0.0, left: 0.0, bottom: bottomHeight, right: 0.0)

Hope this helps!