I have a 3 monitor setup. My main monitor is a UHD monitor capable of 3840x2160. Windows resolution is set at 2560x1440. I have 2 1080p monitors as well (1 on each side of the main monitor) When I set the resolution in the game (exit and restart) the resolution never changes. It always stays at my desktop resolution.
When I load up the game, I get audio from the intro movie without any issues (A little on the low volume side, but it has been that way since beta) All through the tutorial and starting the campaign, I get no audio. The intro movie that plays when you start the first mission has no audio either. I have the volumes set to max on all 3 options with no audio.
During the beta periods that I did play (Not many) I had audio. Since launch, nothing. I am using on-board audio.