I am following the procedures to connect my Google Nest Smart thermostat to Google home app. I get to the point where I am told that I will need the last four digits of the serial number. I have those numbers but I am not given a place to enter their values. Page is frozen until I back out of it. I am using an android phone system.
Sorry to hear about the trouble adding your device. I wanted to follow up and see I could be of any help. I found an article with some troubleshooting steps. Please let me know if you are still having any trouble from here, as I would be happy to take a closer look and assist you further.