Middle mouse still cant be rebound

With cheating still being at an insane rate, why cant I rebind middle mouse to interact with the scoreboard???? My middle mouse doesnt work, idk why, its fine on other games, but in this game it doesnt receive the input.
So guess what? when I get a cheater in my game I cant report them until the round is over and half the time the game ends or the cheater leaves before I can report.

How is this simple keybind still not able to be rebound???