This was the problem. The post is to thank who ever suggested that it might be due to a WIFI extender. I had initially set this up when my extender in the cellar was not being used. I have a Sonos speaker there and the Geek squad was here to fix a problem with my upstairs Sonos. Although there was nothing wrong with the downstairs one, they suggested turning on its extender, which I did. I few days later I when to the Nest app to make some changes and it reported that the upstairs thermostat was offline. I tried calling the NEST help desk but after verifying my account, it asked me to hit 3 to get help. I hit 3 on my phone and nothing happened. Very frustrating. But all's well that ends well but I can tell you the help on this is woefully inadequate.
