no sound in quest 2

After quest 2 updated, playing MP4 film no sound and usually handicapped in Skybox app, need reboot the quest 2 to reuse the Skybox app.

Please click "Global Settings" and turn on "Show FPS" to check the version number. The latest version is 1.1.0(543).

Besides, do you play videos from Quest local storage, or stream videos from your computer to headset via SMB, DLNA or AirScreen? 

Is the sound issue fixed by rebooting your Quest 2?

Looking forward to your reply. Your answers will help us better see what happened and help you fix it.