Okay...I don't get those pop-ups on my iPad, that's why I didn't catch what you were talking about.
Not sure why the pop-up is empty or what it is supposed to say, but when "an-" is prefixed to the adjective, it does not need "go". I don't know if Irish grammarians would say that the "go" is no longer needed, or if it is considered as "included" with the intensive prefix.
Sorry I can't be of more help....
Dale D