HBOMax on TV shows purple screen not loading

We were able to watch a whole movie on 12/22 and now we are unable to login to watch another. It doesn’t even show the login screen. It says “you are connecting to a 3rd party” and then nothing, a purple screen. I can open and watch a movie thru HBOmax on my phone and laptop but not on the TV. We have an LG TV so it says it’s opening via the Internet. We updated the TV. Updated our Xfinity box. Unplugged the modem. I even signed out of all devices from HBOmax. Everything we could think of. Please help! Why work one day then not the next.