UIStackView inside UIScrollView, grows until maximum height then scrolls
Add this
label.setContentCompressionResistancePriority(UILayoutPriority(rawValue: 1000), for: .vertical)
or comment this block
let constraint = scrollView.heightAnchor.constraint(equalTo: stack.heightAnchor)
constraint.priority = UILayoutPriority(rawValue: 999)
constraint.isActive = true
or make this lower than 750 ( the label's default vertical compression )
constraint.priority = UILayoutPriority(rawValue: 749)
the problem is that the label's vertical compression priority is lower than 999 which always make the stack equal to the scrollview height , hence no scroll