ARRIS wifi modem should work with any mesh system.  One of the mesh unit should be connected to the wifi modem via Ethernet port (WAN port on the mesh unit to LAN port on the wifi modem).  From there the additional mesh units can be installed following the instructions from the mesh manufacturer.  The benefit of using ARRIS mesh system with ARRIS wifi modem is that the entire network can be managed by a single mobile App.  With this setup, both the wifi modem and the mesh system act as routers with its own wifi SSID, aka double NAT, it’ll function just fine but the clients connected to the wifi modem would not be on the same network as clients connected to the mesh system and in certain cases they could be a problem, for example, to share files between PCs.  To avoid double NAT, the wifi modem can be configured to run in bridge mode, to disable the routing feature including WiFi, so the mesh system becomes the only router on the network, and the wifi modem essentially becomes a modem.