This is a broken key on the keyboard. You should check one by one to see which one is wrong. When you find it, turn off the computer, take out the battery and gently remove the key cap. The belt buckle breaks easily. Be careful, wash with alcohol and cotton, dry or air dry. It's best to clean up all the keys around, and it will usually be fine. If the flexible printed circuit board is broken, it will not work, and only the whole keyboard can be replaced.