Note: This is the iOS 13 beta, but also could apply to the official release tomorrow.
Update 2: I replaced it with a larger thumb
I had the same issue and managed to resolve it by doing the following:
Add a panGesture ,that does nothing, to your sliders and set their cancelsTouchesInView propery to false.
let panGesture = UIPanGestureRecognizer(target: nil, action:nil)
panGesture.cancelsTouchesInView = false
slider.addGestureRecognizer(panGesture)
Now your sliders should slide like a knife cutting a butter with no swipe interruption.