I have set an id and password but still can't buy Apple TV. Caught in a loop.
I had a subscription in the past, so I had to set a new password this time. I did this. Then I used my tv remote to open AppleTV and watch. But after I enter this information, it asks me to "Buy" or "Cancel". I enter "Buy" and it tells me I have already purchased the subscription and sends me back to previous screen.