Some Sounds are Mute

[Night]

I have a very strange issue. When I fly in DCS A-10C, I cannot hear any "system" sounds like bitching betty, RWR, AIM-9 grumble, or the cannon. However I can hear the engine and APU generator, as well as nearby aircraft. Has anyone heard of this issue before, or how to resolve it? I ensured all sounds in Options (except music) are turned all the way up but the issue remains.