X7 connection freezing after equipment upgrade

I replaced my older gateway yesterday, after I was prompted by Xfinity to order a new device.  I was having no problems with the older equipment, and since I've installed this new X7 Gateway, I've had nothing but problems.  It was a MAJOR pain to activate, which left me without connection for a couple of hours (I work from home, not ideal).  Once I got that worked out, I noticed that the connection would kind of "freeze" and go offline every once in awhile-on my wired connection desktop.  Fast-forward to attempting to stream television last night, forget it.  It froze and buffered about every 2-3 minutes and was unwatchable.  Anyone have any suggestions what to try in order to correct this?  

3 Ethernet ports used, 15 or so devices connected via WiFi.