Get message from Gadgetbridge

I'm having the exact same problem as Purple-Tentacle was having. I can get gadgetbridge to control music on my Android phone, but I can't figure out how to get it to return info such as the artist name, etc. How do you use the GB function to do that? The following (taken from the espruino gadgetbridge docs) just gives "My Artist" and not the name of the artist of the music being played.

GB({"t":"musicinfo","artist":"My Artist","album":"My Album","track":"Track One","dur":241,"c":2,"n":2})