I have a similar problem in a custom subclass of UIApplication
MyApplication.swift:37:21: error: method does not override any method from its superclass
open override func open(_ url: URL, options: [UIApplication.OpenExternalURLOptionsKey : Any] = [:], completionHandler completion: (@MainActor @Sendable (Bool) -> Void)? = nil) {
UIKit.UIApplication:24:26: note: potential overridden instance method 'open(_:options:completionHandler:)' here
@MainActor open func open(_ url: URL, options: [UIApplication.OpenExternalURLOptionsKey : Any] = [:], completionHandler completion: (@Sendable (Bool) -> Void)? = nil)