My Nest App is connected to my Google account. After setting up 4 homes in the Nest App, only 3 of them would show as online at the same time. I tried all the troubleshooting advice, including restarting the broadband router at the 4th home. The 4th home was always connected to wifi, but once I left the house, it went offline in the Nest App. I saw the advice that you can only have 3 homes if signed in with Nest, but 5 if signed in with Google. As I'd already set up 4 homes in the Nest App, I assumed I was signed in via Google & all should be well, but it wasn't. Eventually, I checked my Google Home App, & could see all 4 homes were in there. After that - hey presto! - all 4 are now consistently online in the Nest App, where i can set up or change schedules for every one, and, crucially in my case, lock the thermostats set to an adjustable temperature range of my choosing. Accessing the 4th home through the Google Home App at least once appears to have solved the offline problem.
