Xfi app keeps asking me to upgrade, gives me an error when I try, won't work without it

I just got a  Xfi Gateway self-install kit. I installed the Xfi app for iOS, but it immediately told me "To access xFi, you'll need to upgrade your service/equipment.” There are no other options in the app to proceed beside "Upgrade now." I click through to do it, sign in, verify my address (it has two in the system, one is my old one) and proceed. It tells me "You have the latest equipment," but suggests I can upgrade anyway. I click upgrade because it's the only option. Inevitably I hit the same error: "We're sorry. It looks like you'll need some help managing your equipment. Please contact us and one of our friendly and knowledgable representatives can help."

I contacted a friendly and not very knowledgable representative, who walked me in circles on the phone for over an hour, suggested that she needed to connect me with someone who specialized in the Xfi app, put me on hold for five minutes, then disconnected the call. She was able to manually set up the SSID and password for me, but I can't change it without the app, which always brings me back to the "Upgrade now" screen and is therefore useless.

People in threads like this seem to have experienced the same error and resolved it with the help of someone at Xfinity. Maybe someone more competent than the tech I talked to on the phone is reading and can help resolve it for me.