I have a simple WKWebView app in SwiftUI. I have no problems sending and receiving messages from the native code to the JS and vice versa, except when the message is triggered by an app switch, I am using

WebView().onOpenURL(perform: {url in
                let coord = WebView.Coordinator()
                coord.paymentResponse(url: url)
            })

but anything called by onOpenURL can't send messages to the JS inside the WKWebView. The app continues to work fine when messages are initiated through other means after the switch. Ive tried leaving a delay incase the JS isn't loaded, but that doesn't work. Is this a security feature? I don't get any errors the messages simply don't arrive.