Nighthawk Wireless Router with Xfinity Arris kicks off internet every 8-14 hours

I have a Netgear AC3200 wireless router in access point mode taking a signal via wired network from an Arris Xfinity (white) modem. We got this modem from Xfinity over the past month and the internet goes out all the time. now it is happening every 6-8 or so hours. When i unplug/plug the Arris modem it comes back on and works fine for a short period of time. The Nighthawk (and various extenders that i have also in access point mode) work fine again once the signal comes back after the Arris reset. Has anyone heard of incompatibility with these two products that could be causing this?

I have ordered a Netgear modem to try that in place of the Arris to see if it solves the problem.