I just switch to Xfinity internet yesterday. I have a TV box (Unblock Tech TV Box) that works fine with ATT. I cannot access several apps and it kept saying loading data. I took my TV box to my sister's house that also has Xfinity internet without any problem. Is there any setting that needs to be changed in order for me to run the apps?
The two WiFi bands have recently been combined into one with the Comcast gateway devices. Some devices get confused and don't know how to see / talk to combined bands.
If you are not using any Xfi Pods, you can try separating the 2.4 and the 5.0 bands and give them two different broadcast names / SSID's;