Can't find matchmaking games / Unrelated Audio Bug

I am unable to play any multiplayer matchmaking games as my game just sits in searching endlessly and never finds matches. Any idea what’s going on / how to fix this?

Also, unrelated, I’ve noticed an audio bug when moving the mouse cursor over the unavailable “Games Included” such as Halo 2, 3, etc… Basically, it continues to make the sound during mouse move instead of just on entering.