I just got a Google Nest WIFI and was trying to set it up. I followed the instructions and connected it to my modem, downloaded Google Home on my iPhone and tried to set it up. Everything went well in the beginning. I found the device on Home, scanned the QR code, connected my phone to its WIFI (with the default name) and was able to use the WIFI, then "problem connecting to cloud" jumped out. So I wasn't able to finish the setting or change the WIFI name & password.
I have tried to restart the app, the modem and the Nest(several times). I even tried using Pixel 2 to set it up but also failed. I saw in the community that other people are facing the same problem, so I'm wondering has the tech team found a way to fix it? By the way I'm using it in China, is that the problem? I used VPN though.
Google/Nest WiFi is not supported for use in China, and is unlikely to work there. The units themselves need to be able to connect to Google's cloud services. So, having your phone on a VPN isn't enough.
Unfortunately options are pretty limited for using hardware in regions where it's not supported. Some things work fairly well, but when the devices rely on cloud services, it gets a lot trickier. I can't think of a way to get things to work fully in China, but if you can find a workaround, it would probably be a big deal for lots of people in a similar situation. Your best bet is probably to find a solution that's designed for the local market and work within that ecosystem.