USSD calls with * and # dont work iOS

I have an application that needs to make a USSD call, but on some devices the * and # don't work on the dialer, on others it does.

if let phoneNumber = ussdNumberTextfield.text {
    let encoded = "telprompt:\(phoneNumber)".addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed)!
            if let url = URL(string: encoded) {
                if  application.canOpenURL(url){
                    DispatchQueue.main.async {
                        self.application.open(url, options: [:]) { success in
                            
                        }
                    }
                }
            }
        }