Hello usertomcat,
Welcome to Apple Support Communities!
If we understand your post correctly, you have a subscription to HBOMax through Apple but your Samsung TV is not recognizing the subscription. We'd like to help!
According to the requirements for HBO Max, your Apple TV must be on version 12.2 or higher. With that said, let's try updating the Apple TV by following the steps in the article below.
Update your Apple TV
We also recommend checking out the HBOMax Help Center for help with the app.
Let us know if you have any questions.
Thank you for using Apple Support Communities.
Take care!