ActionSheet crashes on iPad, not on iPhone

Question

The below code is found on examples in several places and used to work for me, but now it crashes. The problem seems to be on iPadOS since it seems to work on iPhones, both simulators and physical devices.

The error is:

'UIPopoverPresentationController (<UIPopoverPresentationController: 0x155e1b5f0>) should have a non-nil sourceView or barButtonItem set before the presentation occurs.' terminating with uncaught exception of type NSException

Is this a bug on iPadOS or am I doing something wrong?

import SwiftUI

struct ContentView: View {
    @State var showSheet = false
    var body: some View {
        Button(action: actionSheet)
        {
            Label("", systemImage: "square.and.arrow.up")
        }
    }
    
    func actionSheet() {
        let av = UIActivityViewController(activityItems: ["Testing"], applicationActivities: nil)
        UIApplication.shared.windows.first?.rootViewController?.present(av, animated: true, completion: nil)
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

Answer 1

After seeing lorem ipsum's reply, I changed thing so the following and it works for both iOS 15 and and before.

func actionSheet() {
        let av = UIActivityViewController(activityItems: ["Testing"], applicationActivities: nil)
        
        av.popoverPresentationController?.sourceView = HostingView(rootView: self)
        UIApplication.shared.windows.first?.rootViewController?.present(av, animated: true, completion: nil)
    }
    
    class HostingView<T: View>: UIView {
        
        private(set) var hostingController: UIHostingController<T>
        
        var rootView: T {
            get { hostingController.rootView }
            set { hostingController.rootView = newValue }
        }
        
        init(rootView: T, frame: CGRect = .zero) {
            hostingController = UIHostingController(rootView: rootView)
            
            super.init(frame: frame)
            
            backgroundColor = .clear
            hostingController.view.backgroundColor = backgroundColor
            hostingController.view.frame = self.bounds
            hostingController.view.autoresizingMask = [.flexibleWidth, .flexibleHeight]
            
            addSubview(hostingController.view)
        }
        
        required init?(coder: NSCoder) {
            fatalError("init(coder:) has not been implemented")
        }
    }