As reported on many threads (eg. https://community.netgear.com/t5/Orbi-App/Orbi-app-not-showing-all-connected-devices/m-p/2083827#M31...) there is an issue with the Orbi Netgear app for IOS to manage the RBR850/RBS850 when it comes to the display of attached devices. After a kind of timeout there is just an error message and no single device is shown. The only option is to go to the web interface of the router from the WAN: there all connected devices show! So the problem is really about the IOS app way to get the info.
