I just figured this out. Wife has a iPhone and I have Samsung. She has RCS but drops when connecting to just our router. Anyone's else's router is fine. We have a Netgear nighthawk and the solution is go to routerlogin.net when on the local WiFi and input your login info so you can change the router settings. Go to settings-vlan bridging- allow Port 1 and only the 2.4g (or you'll be factory resetting the router it has a bug) then apply and it'll reboot. RCS messaging is not longer an issue.