I have 2 houses with 3 nest thermostats. The app only supports one location, always shows incorrect outside temp at the vacation house. Primary residence is accurate, vacation home never recognizes the correction location to obtain outside temp, always refers to primary residence location. I reset the Vacation home nest, I created a Google Home account with only the Vacation Home address. Google Hone app will NOT allow the Vacation Home Nest device to be added. I scanned the Nest QR codes and it does nothing. Seems like such a simple change but it does not work.
Home app did not work as I explained in post. I saw the same feedback from an earlier post. In my case, Home will NOT add my Nest as a device nor to does it find it when searching. I reset the Nest, still Home will not add the Nest device. So, no device, nothing to tie to an address.
Have you looked through the help pages below? Both the Nest app and Home app support multiple homes.