DVR playback/Netflix stutter issue

So, I've had Xfinity for about 6 months now. I decided to add a box to my bedroom about 3 months ago. Ever since I got my xI6 set top box for my room, I've had nothing but issues. I went with the box, in hopes to be able to watch live 4k content as it comes out...for example the Superbowl. I figured it would also be a better experience than the Stream Beta app. Well to my amazement, the Stream Beta app not only has better picture quality, it has no issues with frame rate skipping. I also have no issue with Netflix skipping when I use the app via Roku. Once I go to Netflix thru xI6 box, I notice it immediately. This is very frustrating as I'm spending money on a box that clearly has issues. Idk if it's the box itself or the firmware, but something is clearly wrong. I can't watch TV at all with this box anymore, unless it's live, and still I run into occasional issues. I've seen I'm far from the only person with this annoying issue. Most posts are from over a year ago...why hasn't this issue been fixed? Does anyone have a fix, other than getting rid of the box? I've checked everything. All connections secured, good signal, system refresh and reset, etc. I don't notice these issues on the main xgIv4 box in my living room, only on this xI6 box. I figured it's due to the one being hardwired, and the other working over WiFi. All I know, is there's an issue, and dealing with Xfinity is unpleasant from previous experiences, and most of the time, I know the tech better than the people on the other end of the phone, or the installer. That's another thing...the installer, installed the wrong equipment in my house to begin with. He knew we had 4k TV's, paid for Netflix UHD package, etc....but he installed older 1080p boxes instead. That just doesn't make sense to me. So I had to take a trip to the Xfinity store to get new boxes myself. Like they say...if you want something done right, you're going to have to do it yourself...