Xfinity App does not show my internet service

I've had Xfinity for years and never had an issue using my own personal modem until last week.

Suddenly the modem doesn't allow me to sign in directly with my own password and forces me to a sign in page that directs me to download the app (which is already downloaded.)

When I go to the app via that page it routes me to Google play store - open app... And then the app opens and tells me "Something went wrong" and forces me to sign out of the app.

Now I have no way to connect to the internet without the connection not being private and nothing will work.

I've gone through four separate chats with the tech people and they are telling me I will have to pay $100 for a technician to come to my house.

The app, when I sign is doesn't even show my internet service so there's no way to manage it there, regardless of the sign in issue with my modem.

The only service that shows on the app is the stupid basic cable that was established by the HOA.

I'm beyond frustrated. I need someone to help figure out why the app won't show my service at all, and why I'm being forced to sign in to the app to sign into my modem.