Unit stops working after 10-15 minutes of operation. All known troubleshooting options have been taken. Defective unit?

My AppleTV unit is less than one year old (11 months). It was installed by a professional and worked perfectly for several months. I primarily use it to stream video. In the last two months, the unit began flickering and buffering frequently and continued to not function correctly up to the point that it now will stream video for 10 minutes and go black (video and audio stops). After a few minutes and then restarting, it will not access menu. I have bumped up internet speed, updated firmware, and tested WiFi video streaming on other devices, all to no avail. So, I'm assuming the unit itself is defective. Free AppleTV support is no longer available for this unit. My tech says he has never had any units fail so, I'm questioning if there are any other options or troubleshooting I could try. Thanks