I thought the update two days ago fixed it, but I just opened some 1080p mkv (h264 I think) movies with 5.1 AC3. I’m still having a stuttering issue on quite a few of them. D-Pad workaround will fix it for a couple of minutes and then run into the same issue. If I don’t hit the D-Pad, the screen will turn green and show some digital artifacts.
I’m showing 20+ download and 15+ upload on network connection tests (connected via WiFi to a gigabit service), so bandwidth is definitely there to support it. I did not have this issue until the NXOE update. A 1080p movie that played fine before will stutter on NXOE.