I bought an Arris SURFboard SBG6900-AC a couple of years ago so I wouldn't have to pay a modem rental fee each month. I thought at the time I was buying a higher-end modem. Both my previous Verizon Galaxy S7 and current Verizon Galaxy S9+ get pop-ups every once in a while saying wireless has been disconnected, but it reconnects right away. My Chromecast, Fire Stick, Echo Dots, and Google Home Minis don't seem to have any issues. But my wife, who has had the same two phones, has always complained that her wireless disconnects all the time. And when my two nephews come over they complain that they get disconnected all the time unless they're within 15 feet of the modem, which is on the other end of the house from our living room. They use both Apple and Android devices. Any ideas what settings I should check on my modem or what to look for as to the cause?