Everything works fine if the payment process is invoked by calling handlerInput.responseBuilder.addDirective(buyDirective).getResponse() as a response to a normal voice intent. Payment process is started.
However, when I call the very same method with the same content as a response to the event user clicked on a button (SendEvent -> type == Alexa.Presentation.APL.UserEvent) nothing happens. I can see that the correct handler gets triggered and that I'm returning the same output from handlerInput.responseBuilder.addDirective(buyDirective).getResponse().
Is there some internal check that prevents me from calling "Connections.SendRequest" directive as a response to SendEvent?
What can I do to make this work?