Left Align UICollectionViewCells only works when cells are not correct height, and stops working when scrolled - swift

Question

I am trying to left align the cells in a UICollectionView, and I have used a GitHub repo to try and obtain this, link here:
https://github.com/mischa-hildebrand/AlignedCollectionViewFlowLayout
I set up the CollectionView and its cells like so:
lazy var filterCollectionView: UICollectionView = {
let layout = AlignedCollectionViewFlowLayout(horizontalAlignment: .left, verticalAlignment: .center)
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.register(filterCell.self, forCellWithReuseIdentifier: "filterCellId")
cv.backgroundColor = .white
cv.isScrollEnabled = true
cv.dataSource = self
cv.delegate = self
cv.showsHorizontalScrollIndicator = false
return cv
}()
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return genrArray.count
}
let genArray = ["Test123", "LongTextTest", "Short", "S", "#LongLongLongLong"]
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: "filterCellId", for: indexPath) as! filterCell
cell.genText.text = genArray[indexPath.row]
cell.genText.sizeToFit()
cell.frame = CGRect(x: cell.frame.origin.x, y: cell.frame.origin.y, width: cell.genText.frame.width + 25, height: 24)
return cell
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let label = UILabel(frame: .zero)
label.text = genArray[indexPath.row]
label.frame = CGRect(x: 0, y: 0, width: label.intrinsicContentSize.width, height: 0)
return CGSize(width: label.frame.width + 25, height: 18)
}
This did nothing to the cells, so I added these lines of code into ViewDidLoad():
let layout = AlignedCollectionViewFlowLayout(horizontalAlignment: .left, verticalAlignment: .center)
layout.estimatedItemSize = UICollectionViewFlowLayoutAutomaticSize
self.filterCollectionView.collectionViewLayout = layout
The line that actually made a change in the CollectionView was layout.estimatedItemSize = UICollectionViewFlowLayoutAutomaticSize. But this still did not achieve the desired effect. This squished my cells and made them have a height of much smaller than 18 (the size declared in sizeForItem. When loaded up, the collectionView looks like this:
But when I scroll through the collectionView, it reverts back to normal as if the left alignment layout is not even there. It then looks like this:
The cells are the correct shape in that image, but the alignment/layout/spacing is off.
What am I doing wrong?