I saw the thread you shared... I was hoping, because that my issue might be different because I wasn't using an actual Google Home Device... but I guess not. Guess It's time to go to the Alexa app...
I haven't used it in some time (a week or two), but my google assistant on my samsung s8 can no longer see the ISY, apparently google home recently pushed out a new app. It doesn't appear to play nice with the Universal Devices. My Portal is active but when I attempt to push spokens update I get the error below.