Whenever I play 4K mkv files from a usb in the media player app, the audio will skip. Usually once a minute, sometimes more, sometimes less. It makes a movie unwatchable. Also, the new media player app will not let me change audio, it will only play the default audio track. The old version of the app worked flawlessly, please fix the current app or allow the old app to be installed. My Roku TV and Roku Ultra are now basically useless right now for USB media.