I just got a google home hub for Christmas and I almost returned it because it did not seem to work with the ISY portal. But then I saw this thread and my Google Home Hub was saved!
What I did wrong: I use ISY scenes to do almost everything, so I only added scenes to the portal. These came up as scenes in both my Alexa and my Google Home connections. This is not a problem for Alexa, but its a BIG problem for Google Home, because Google Home has its own idea of what a scene is - and it is NOT the same as an ISY scene. A scene in Google Home is not visible and is only accessible as part of a Google Routine. Scenes are not always found by Google Assistant, so voice commands for scenes are problematic
So a piece of advice - make your ISY scenes into Google Switches, or if they are simple, make them Google Lights. (But do not put more than one light in a room or it will get lumped together with all the other lights in that room.) The Google mental model of home automation is just different than the one I am used to from ISY. Once I reset my mental model and changed my scenes to switches VIOLA! I discovered that Google Home works quite well with the ISY portal.
