Delegate methods in UIScrollViewDelegate don't respond to table view scrolling event

I'm trying to do pull to refresh and infinite scrolling to table view without the need for external libraries

I was setting the delegate correctly:

tableView.delegate   = self

But when scrolling inside tableview, scroll methods do not respond to scrolling action for example:

func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {


    if scrollView == self.tableView {
        
        let currentOffset: Float = Float(scrollView.contentOffset.y)
        
        if currentOffset < 25 {                
            //refresh content
        }
        
        let offsetY       = tableView.contentOffset.y
        let contentHeight = tableView.contentSize.height
        
        if offsetY > contentHeight - scrollView.frame.size.height + 25 {
            // load more
        }
        
    }

}

This case happened when I changed the scheme build configuration to "Release", but when getting back to "Debug" it's working correctly.

My deployment target is: 11.0, and XCode Version 10.2 (10E125)

After a lot of search it might be a Swift 5 compiler problem (I found a similar bug reported there):

The solution is to add @objc to each method:

@objc func scrollViewWillEndDragging(_ scrollView: UIScrollView, withVelocity velocity: CGPoint, targetContentOffset: UnsafeMutablePointer<CGPoint>) {

    if scrollView == self.tableView {

        let currentOffset: Float = Float(scrollView.contentOffset.y)

        if currentOffset < 25 {                
            //refresh content
        }

        let offsetY       = tableView.contentOffset.y
        let contentHeight = tableView.contentSize.height

        if offsetY > contentHeight - scrollView.frame.size.height + 25 {
            // load more
        }

    }

}