If you plug in headphones into either the gamepad or the remote and try to watch any movie with HD audio tracks while passthrough is set to auto, the app will report a server and app error and the file will not play. When passthrough is set to disabled the files will play perfectly.
It's a pain to have to switch that setting back and forth just because I use headphones occasionally. The app should query the OS and detect headphones connected, and then temporarily disable passthrough until the headphones are disconnected.