Mouse Issue In-Game

I purchased the DLC pack yesterday, downloaded the content, and when I started the game my mouse movement doesn’t work in-game. I am stuck looking straight ahead. In the menus the mouse works fine and the mouse buttons work fine (I can shoot, switch weapons, and zoom). I have tried switching the view, quitting and re-starting the game, re-starting the pc, re-loading the mouse driver, plugging in a different mouse, and the results are the same. I appreciate any and all suggestions. Thanks.