I am having the same issue. I use the google home wifi and the Arris SBG6700-AC as my modem. Everyday the connection drops but the modem lights appear connected. When the connection is out, I hardwire in with an ethernet cord, and the connection is not there and I am unable to ping any ports (Google: 126.96.36.199). Comcast has sent numerous technicians and the same issue still occurs. I also contacted Arris who replaced the modem, yet the issues still continue.
Does the Arris SBG6700-AC need certain settings for the Comcast connection?
Do other modems work better with Comcast?
Start with the modem's signal stats. Perhaps they already are, or they are close to being out of spec and intermittently they go completely of spec. Try getting them here http://192.168.100.1 or here http://10.0.0.1
Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.