I've been tweaking the various settings in my game to get it configured just the way I want it. However, recently I've noticed that whenever I visit the settings menu while playing a game and then return to the game, the game's sound becomes really low to the point where I can just barely hear the voice alerts and even more barely the interface sounds. This happens despite me not altering the sound sliders.
That's a deliberate feature. I have no idea why it's there but I agree that it needs to change, you'll get used to it eventually.