I had the exact same problem with the audio/video cutting out and a usb bluetooth receiver for a gaming controller losing connection at the same time while gaming at random intervals.  As soon as I uninstalled Dell support assist the problem went away.  Definitely worth a try if you're having similar issues.  Thanks to the above user
Just bought this PC last month and am really happy with it.  It's super fast and I'm now getting my full cable internet speed over wireless (100+Mbs).  However, I noticed while streaming video or trying to record myself playing guitar, or playing games, it will randomly stutter...sometimes after several minutes, sometimes less, but it's frequent enough that it's annoying.  So, I decided to start removing / stopping services until I could isolate what was causing the stutter.   Turns out that it is SupportAssist.  Once I stopped that service, the stuttering seemed to disappear.   I have version 3.13.0.236 installed.  I noticed some very old threads here after searching that indicated this used to be a problem.  Seems to me, it still is. I'm not looking for assistance.  Just want to put this out there in case someone else experiences the same issue, and just in case Dell might like to look into it and fix it.  For now, I can live without SupportAssist unless I run into a problem that I need to report.    
XPS 8950 - Video/Audio random stutter fixed by disabling Support Assist