I've seen other threads about this issue, and it could also be a bug. The Scroll View contains only UI elements (Image, Text, Button, Panel, and anyway I need to scroll these components) and has a white-transparent Image source. But even putting it in full color the result does not change. In Viewport the Mask component has ShowMaskGraphic on, even if I ignore the utility of ShowMaskGraphic. Problem: in Unity everything works perfectly. Compiled for Android the Content is all visible, even outside the Viewport. I have at least two Scroll Views in my game, and both have this flaw. Platform changes the result!