SO I was dealing with a problem today where my tv would turn on fine and navigate to any app. However, as soon as I decided on one and clicked it, any show/movie/etc. would not load on any of my apps. Optimization and cache clearing/etc. would not fix it.
FIX: All I had to do was go to settings, device preferences, quick start, and disable quick start. Then, turn tv off and back on and everything was back to normal. You can enable quick start again. Hope this helps someone in my previous position!
worked like a charm! thanks