It happened to me 2 days ago as I was streaming a couple of videos.As I switched to another video,it failed to play.I then tried a few other videos and all I got was the rotating 3 dots.I closed the DEOVR app,switched off the Quest2 head set for a couple of minutes,switched on and tried again,thankfully it worked.Since then,it happened a few times.I hope it works for you too.