Arris gateways were known to have dropping issues when used as a home gateway. I recall something about changing the DHCP scope away from 0.2 -0.9, as those addresses seemed to be most affected. I think there was also an issue with high active/open connections causing them to overflow and reset the network stack. (this was many years ago - I would have assumed it would have been addressed by now)

The Arris gateways aren't really designed to be run as complete network gateways. They're best used as a bridge to a dedicated router if stability is something you are looking for. I'm still running an old 54G as a wireless bridge in front of the miners and use an RT-N60 for my main router.