I have the same problem with a Roku device plugged into an android TV. The Roku device drops several times a day, but the TV, other android devices, and laptop stay connected. As a workaround, I restart the AT&T 2.4GHz wifi on the AT&T All-Fi Hub from a Chrome web browser on an Android device. It takes about 15 seconds; the Roku device usually reconnects on its own; sometimes it's manually. That way I don't have to reboot or unplug any devices. I saved the Hub Ip address as a favorite and Hub password in Google to keep from retyping everything.
