SOLVED: Access Not Authorized when trying to login Xfinity App

I finally gave in and upgraded to the Xfi Gateway Complete plan/modem due to going over the 1.2TB data cap. I was using my own equipment/Motorola wifi-modem

UPS dropped off the new modem, I hooked everything up, but in order to activate the modem, you have to download the Xfinity App. When I tried signing in to the App, the Xfinity login page displays  ACCESS NOT AUTHORIZED you signed in successfully, but you must be an Xfinity user to enjoy this service.

Mind you, they want you to use the app to activate service on their equipment. I couldn't do that so, I reached out to Tech support. Spoke to a rep from Colorado, very helpful and got the new modem/network up and running. Took about 30 minutes. I still wanted to have access to the Xfinity App to check on network other features, so she transfered me to another rep. He tried helping, made me reset password., then transferred me again to another specialist,I tried deleting and reinstall app, tried signing in on my iPad still getting same issue. He gave up and said someone will contact me tomorrow.

After that I started to look into My Account and notice that when I logged in, it had my old account/inactive as default. I went ahead and selected MANAGE ACCOUNTS it displays both of my accounts and an option to select my current account/address as DEFAULT. After saving the changes, I went ahead and was able to sign into the Xfinity App with no issues. 

This should solve issues with customers signing in and have multiple accounts, for me I had an account at an apartment, disconnected service and a few years ago setup a new account in my home 

Hope this helps.