Replying to myself: This problem occurs in Xcode 16.1 but does not occur from 16.2 onwards. I had earlier version.

Same here, one way to fix this temporarily is to set detent directly on presentationController within sheet's content .onAppear { guard let windows = UIApplication.shared.connectedScenes.first as? UIWindowScene else { return } if let controller = windows.windows.first?.rootViewController?.presentedViewController, let sheet = controller.presentationController as? UISheetPresentationController { sheet.detents = [.medium()] } }