In my account several buttons advertise Flex as available to my account. I click to add and go to a page with 2 options - Add 1 box for Zero Dollars and 2 Boxes for $4.99/ mo. . In the upper right there is a go ahead button that dissappears if I select either of the options. If then throws an error which says "Select an Option" or words to the like. The options are grayed out - unavailable, and then the "Go Ahead " button dissappears as well. I have tried the website signed in to Chrome, Firefox, and the New Microsoft Edge - All are No Go.
So Hey Xfinity - Ya Website is Broke!
Flex isn't compatible with an account that already has a TV box. You have to switch account types to get the Flex offer to work. It's a bug in the offer logic that makes it tell you that you can get one. Talk to an account rep to get your account type changed. You'll need to return your regular TV box.