With my new Orbi, I could not access certain websites. It would ask for login credentials, which wouldn't work, and would even appear for websites that do not require a login. I was also getting a 401 Authorization error on some websites, like orbilogin.net. I have AT&T U-Verse with a modem/router combo. I finally found a solution.
First, I had to disable the AT&T WiFi by going to the router/gateway IP address and disabling each WiFi network. Netgear has a video explaining this (just Google "How to Turn Off WiFi on your AT&T U-Verse Gateway"). There's some issue with multiple WiFi networks competing with eachother. Although I had both running for a while and both worked (but with Orbi only working on some websites).
Second, I called Netgear's customer support, and they asked me to use a laptop or iPad to visit orbilogin.net. I'd already done this, but evidently, the login credentials require a username of "admin" and then your Orbi WiFi password. I'd been trying my netgear login and my WiFi network name. Once I logged in as "admin", it notified me that the IP address was changing from the default to avoid conflicts. And then the issue was fixed without going any further on the Orbi website. Yay!
