In the latest update, the SyncVideoStream audio don't function properly if you're audio set up isn't correct.
What I mean with isn't correct is that if the current audio output isn't set as windows default output, then the SyncVideoStream will use the default instead of the current active. (Thank you Temporal finding this)
Not sure if it will affect everyone having multiple outputs, but different depending on what one is doing.
So if you have another output set as default before you start VRChat, then switch while loading/in-game, then go to a world with the stream player and play a youtube video, you'll notice that the audio doesn't work. However, if you switch back to the default audio output, then back again it will work. But only till the video ends.
Once you start a new video, you'll have to redo the steps again.
It's a very strange one and does not affect everyone. But there are some.
It might also not be the case for the default audio, but not actually getting the output at all for the player?
Repo (Still not sure if this will work for everyone);
  • Set another output as default audio.
  • Load up VRChat
  • Switch to primary audio output
  • Start a youtube video in a Video Stream player
  • No audio being played.
  • Switch audio back to the default one
  • Switch back to primary output
  • Audio will now play