My Game Camera Won't Move Properly

[Canis Libra]

I can't seem to find a solution (or even another person who has had this issue) anywhere online. I'm new to Squad and have never played it before. The first time that I play it, I decide to go into the Training. But instantly there's a problem. I can't move my camera in any direction other than up and down. To be more specific, the game starts me with the camera facing East. I can look up while facing East, look down while facing East, side step to the left while facing East, side step to the right while facing East, walk forwards while facing East, and walk backwards while facing East. But I can't face any other direction that East. Moving my mouse around only makes my camera look up and down (while facing East of course). And I know it's not supposed to be like that. The tutorial even tells me to use the compass and head north to my next objective. But of course, I can't do that, cuz I can't face any direction other than East. At first I thought this might be an issue caused by my mouse not being compatible with the game, so I bought a new gaming mouse. Same issue occurred. I tried reinstalling the game, same issue occurred. I've tried messing with the settings to see if there was something with the resolution or other that could be affecting my mouse and/or camera. Nothing worked. Please, if anyone knows what's going on here, I could really use some help.