Recently I have been having issues with movies and TV shows. It's like the content gets displayed at a low frame rate. Like playing a game on a PC that isn't powerful enough. It happens on local content, YouTube, Netflix, Hulu, etc...
It seems like this started after the latest update. Has anyone else been experiencing this?
Really can't say that I have.
You could always try out Kodi/SPMC, it has its own info panel that shows everything like framerate, framedrops etc. so you can check if it happens there as well.
If it does, try a reset of the Shield TV and if it still persists something is obviously broken.