Apple/Smart TV issue - Suddenly not playing HBO/Netflix (Smart TV will still load Netflix)

Our Internet is running perfectly, and Netflix/HBO Now will load fine on the laptop, but will not load at all when I hit "resume play" or "play from beginning" on the Apple TV for both Netflix/HBO Now. The Apple TV is updated to latest version. I've also tried resetting it. When I go to play Netflix on the Samsung Smart TV, it loads up and plays just fine with great quality. However, HBO Now won't load on the Smart TV. Yes I've tried unplugging stuff and turning off and on and all that jazz. Tried testing them at multiple points during the day on multiple days, seems to be consistently bad.

We've been using our Apple TV to watch Netflix/HBO all year with no problem. This just started up about a week ago. I'd think the Apple TV would be the culprit, but HBO Now is acting really poorly on the Smart TV too. We have Cox. Hoping it's not a Cox issue, because I know it will never get resolved.

Any help would be appreciated. Thanks!