At my wits end.

after countless hours troubleshooting the issue with Google/Nest customer support and advanced customer support as well as two RMA's for a new TSTAT, I am still not able to successfully connect my new Google Nest Generation 4 thermostat to the Google Nest server. During setup it always fails at the very last step, right after connecting to WiFi. It generates a 0.80 error message, stating that something went wrong and the TSTAT is not able to connect to the Google Nest services. We just removed a Generation 2 Nest TSAT (as support of this device is ending). This is a last resort, I feel secure in saying that I believe all of my wireless router settings are correct, no access control, no firewalls, router is generating both IPv4 and IPv6 IP's we have 35 other devices successfully connected to wireless router. We have a Motorola surfboard DOCSIS 3.0 modem and a Netgear R7000 wireless router. Distance/signal strenght isn't an issue. I am hoping someone has experienced this issue as well and would be willing to share with me what the resolution was. Thank you in advance.