Why is HBOGo doing this?

[ajtoole]

Whenever I log in to HBOGo with my brand new MacBook Air, I type in the credentials and when I hit "submit," the login screen ends up looking like this. It won't just log in and let me watch, it becomes a smaller box and I can't do anything with it. Any idea why?

 

[T5BRICK]

Have you tried using a different browser?

 

[ajtoole]

Yes, I've tried both Chrome and Safari