Not sure what to tell you. Which OS / browser?
That is a solution to your problem, but comes with problems of its own: it would cause the game to eat keystrokes it can't handle and shouldn't, like pressing F12 to bring up a console, or ctrl-d to bookmark, or whatever. Since the problem only seems to happen if you have that setting set (which doesn't seem to be the default since I've never heard of it), I suggest clearing that setting, rather than me breaking non-game keyboard input for everyone else.