Modem reboots - help with troubleshooting Arris SB8200 - Time Warner Internet

This question is about "Modem reboots - help with troubleshooting Arris SB8200", with Time Warner Cable internet and apps. Hi - I've been having really bad reliability with my cable connection/modem. Everything seems solid (good ping and download/upload speed), except I'll see seemingly random reboots of the Modem.

Config is pretty simple: Cable into the apartment (from the roof of our pre-war walk-up), direct (no splitter) onto an Arris SB8200. The Arris gives an internet IP via Cat5e cable to pfSense router onto the rest of the network. The pfSense router is rock solid, I recently built a new pfSense box with new hardware, with completely vanilla settings (i.e. NAT, DHCP etc.) - not to troubleshoot this specifically, but handy to confirm.

This is an internet only subscription.

SpeedTest results (when the connection is working) are solid and consistent:

- Down ~246Mbps

- Up ~11.8Mbps

Pinging google DNS (e.g. gives me a latency of ~12ms

I'd previously used a Netgear C6300-100NAR - that was bought as "Refurb" from amazon, and replaced with the Arris in the hopes of fixing the issue (no change in symptoms since changing the modem to the Arris)

Details from the modem below:

Modem reboots - help with troubleshooting Arris SB8200?