I recently installed a nighthawk rax200 to my fios gig router. Everything works great and the speeds are exceptional. For some reason, the nighthawk app shows all attached devices but states that they are not connected to the network.
it's the standard Fios quantum gateway 1100 series, cable/modem
Not much help, but the "gateway" tag is one clue. It isn't a simple modem.
Google also suggests various possible model numbers. One that I found is for a modem/router. If you have one of these, with a bunch of LAN ports on the back, you are running with two routers on your network. That can lead to various symptoms, including the one you described.
Two routers on your network can cause other headaches. For example, you can end up with local address problems. Among other things, the other router can misdirect addresses that the Netgear router usually handles, such as routerlogin.net or the usual IP address for a router, 192.168.1.1.
If things are working OK, you have a couple of options, live with it, or reduce your network to one router. That means putting this gateway into modem only mode, or using the router as a wireless access point. Either option has knock-on implications that you might like to investigate.
