I have a Arris Surfboard SB8200 and the Google Nest Wifi router. Following the instructions I can find the router using the Google Home app. The router then tries to connect to the interenet but can't connect and tells me to restart the modem and router. I've done this too many times to count.
I had a older version of Google Nest wifi. I had to turn the power off when I was doing some electrical work. When I turned the power back on, about an hour later, they would not reconnect. I thought maybe a power surge had caused a problem. The modem works fine. I decided I wanted the newest version of the Google Nest Wifi, bought them and am now having the same problem.