Make sure that the Netgear Orbi RBR50 router and RBS50 satellite have been synced properly. The Sync button should be pressed on both of them. The Ethernet cable that you have used for the connection between the networking devices ought to be damage-free. Also, it should not be worn out. There should not be more than 50 feet of distance between the Orbi router and the existing modem... https://orbitloginnet.com/netgear-orbi-rbr50-setup/