Weapon lock bug

Soo,my rangefinder key is “R”
my weapon lock is is pressing the middle mouse wheel,and fire from special guns is mb4.
now when i try to rangefind by pressing r ,my weapon lock gets activated (im an gepard 1a2),and i tried to reset control key binds, change the weapon lock,but the “r” key is stuck on being the weapon lock.how can i change it?