On iOS 26 (reproduced on both Simulator and iPhone), the system share sheet (UIActivityViewController) displays the row of activity/app icons at a greatly oversized scale.
The app's approximate hierarchy is like UIWindow.rootViewController → a plain container UIViewController → UITabBarController → an embedded container child → UINavigationController → the visible screen.
- When the share sheet is presented from a view controller inside such an hierarchy, the icons are oversized.
- When the same UIActivityViewController, with the exact same activity items, is presented from a full-screen modal view controller (modalPresentationStyle = .fullScreen / .overFullScreen), the icons render correctly.
Is this a bug of iOS 26+? On iOS 27 the behaviour is the same.