ATT home internet unable to stream from MLB.TV

I recently bought ATT Internet Air. I am having trouble streaming MLB.TV through ATT Wi-Fi. I have a Roku TV and when I try and open the MLB app it says “unable to establish a connection with MLB.” MLB is up-to-date, ROku TV is up-to-date. So I disconnected from my ATT Wi-Fi, opened a hotspot from my phone and connected it to the Roku TV and now it’s allowing me to open the MLB app and stream. I test the internet connection to my TV and it says it is excellent and I’m also able to stream from other apps, HBO, Netflix etc. So, I figured maybe it’s just a Roku TV to ATT internet issue, however, I am unable to stream any MLB.TV from any of my 3 devices (TV, phone, laptop) using ATT internet. The fact that I am able to connect and stream through my hotspot just fine tells me the issue is with the internet. 

I just got this internet and dont want to go through the hassle of changing to another service. Wonder if someone is experiencing similar issue? Thank you.

ALSO tried factory resetting wifi, moving Wi-Fi, etc. and still no budge.