Access not authorized

I am starting my internet service as a first time customer and need to set up my xFi modem. To activate the modem, I am required to sign in through the app. When I sign in through the app, I consistently receive the error stating "Access not authorized. You signed in successfully, but you must be an xfinity user to enjoy this service." As I am clearly an xfinity user, this is mildly infuriating. Based on previous threads experiencing this issue, I believe I need my xfinity account to be refreshed or resyncronized, but I'm not sure how to go about this. I have done the process at xfinity.com/getstarted multiple times to check if I had any problems with my account or previous accounts I didn't know of, but there doesn't seem to be anything wrong with the account on my end. Could a Comcast representative please help out?