This happens to us as well after updating to 4.14.
One thing we noticed is that the sounds that were stopped after loading a map will start play after we resume the game. We use UGameplayStatics::SetGamePaused to pause/resume the game.
From what we know there is no special case where the sounds get heard, the same sound (we are shooting weapons in an FPS game and one weapon uses the same shooting sound) sometimes plays, sometimes it doesn’t. However, it happens to us with a lot of other sounds, no necessarily sounds you shoot fast or with a certain setup.
Let us know if you find out anything else.