I just played a game on ladder where I had that sound problem, where something happens shortly after game start and you lose sounds for some of the game events.
I think this is an old problem, right, and there were some things to try as workarounds?
(I seem to remember changing the frequency for a sound device to 22000, or something like that, at one point in the past.)
In any case this is something I haven't seen in a while.
I also didn't see any recent forum posts on this.
What is the current state of the art with respect to this bug, likely causes, and known workarounds?