Nest thermostat won't connect to Google mesh router

[Tpommm]

I have a nest 3rd Gen thermostat and I have a Google mesh router setup. I've tried factory resetting the thermostat multiple times but the thermostat will not connect to the WiFi. 

Not sure if anyone else has had this issue.

At this point I'm not sure if it's the WiFi chip on the thermostat that's defective or if there is a setting on the Google router that will allow the thermostat to connect

Thanks in advance 

[David_K]

If this is during setup, try these steps:
Troubleshoot setup: thermostat doesn’t show your Wi-Fi network - Google Nest Help

If it was previously connected to Wi-Fi and is now offline, try these steps:
Nest thermostat is offline - Google Nest Help

It's also worth checking you're not experiencing a W5 error message:
Troubleshoot a Nest thermostat W5 code - Google Nest Help