Hey Fnuabdulrehman2,
Sorry for the delay but thanks for posting. I have some questions to better understand what you're experiencing.
What Google Nest device is not connecting to your WiFi network? If this is a thermostat, what specific type of Nest thermostat is it? Also, are you getting a message or a code? It would also be awesome if you could provide a rundown of the steps that you've already tried so we could pick up from where you've left off.
Best,
Melba
