Screenshot attached. In this example the thing that’s probably different is the fact that in this case it happens for AmbientSound actor (meaning the audio source contained within starts by itself, not played by our code logic). The sound concurrency is StopFarthestThenOldest but I don’t expect it to be a problem, since this happens right on map load and there should be no concurrency conditions happening there.
It happens with other maps as well, they are all similar in setup and I can safely say it happens to all of them (randomly, some maps might play the background sound (selected in the screenshot), others won’t until I resume the game once.
Thanks for getting back to it!
[edit]
Tested the game a bit more. It seems that the only sounds we can’t hear after the fix, are the ones created as AmbientSound Actors. All other sounds (either played by game logic or as sound sources inside custom actors) seem to be playing correctly now.