Difficulty opening HBO Max on my applet tv.

I have been using HBO Max on my appletv; recently cancelled it, when I thought Spectrum Silver provide the same service for free (it doesn't), and paid for it to be reactivated. Although I can stream it on my computer, and although it was working 2 days ago, when I now try to access HBO Max on my tv, the screen blacks out and three sequential dots serially blink at the bottom of the screen. However, HBO Max never loads.