You've run into a new feature of Starling 2.5: an attempt to detect system gestures and ignore them. On both Android and iOS, if you swipe down from the very top of the screen, or up from the very bottom, you're interacting with the operating system, not with the app, and want to open up the notification area, quick settings or an app switcher.
The problem: those touch events are still forwarded to Starling, so oftentimes, players mistakenly interacted with the game when they actually just wanted to change screen brightness.
That's why touches starting 10 points along the top or bottom edges are now ignored. In most games, there are no interactive elements so close to the screen borders, so it won't be a problem.
More information here: https://gamua.com/blog/2019/04/starling-25/
Most importantly, if you don't want this behavior, you can easily disable it:
// new property on Starling: (defaults to 'true' on iOS and Android)
starling.discardSystemGestures = false;