Repeated "You must sign in" prompts when I'm already signed in.

I was trying to troubleshoot internet/streaming, and kept getting the "You must be signed in" prompt.  I click "Sign in" and it's like Groundhog Day, over and over.  I AM signed in, at least I'm pretty sure I am.  I mean, I hope my account information can't be viewed without signing in, and I can see that my bill is due next week.  I finally had to go to my phone and use the app over my LTE connection to restart my modem, which seems to have resolved the streaming issue.

BTW, I'm still getting the "You must be signed in" prompt.