I got this problem after installing Immersive FP, but not right away. Uninstalling doesn't solve the problem for me. I can look side to side, no problem. Can't look up or down. When I go into third person mode, the camera is thrown off the map to some random location. If I toggle Immersive FP back on, it puts the camera stuck to my character's face. I can control the character, but the camera angle doesn't changed. It's so messed up, I don't even know where to begin fixing it.