Anyone know why the game doesn't even recognize scroll left or scroll right with the tilt wheel?

By default my mouse has tilt wheels but the function isn’t recognized by the game. It recognizes it if I bind it to something besides what it actually does. I want it to switch nades left and right but I would have to literally bind my tilt wheel to a letter or something. Rather than just Previous grenade “scroll left” and next grenade “scroll right”. thats All I want.