Either a friend or one of my cousins tried to join me for a LAN game. He said he was using some special mode because the normal mode was not working.

I then noticed the typical 6 key on my azerty keyboard, which types - in lowercase and 6 in uppercase, has been replaced with a key that types - in uppercase and _ in lowercase. This looks similar to the -/_ key on qwerty keyboards, but it was reversed.