The only thing I can think off to this point is a compromise contact (even if green light is on) or a stuck key, mechanically or something stuck underneath one. I might sound weird but hold the keyboard perpendiculat and gently yet firmly knocking it each side twice (8 knocks) and carefully listening for any unsound noice, such as stuff moving aroung either underneath keys or inside the plastic. In my experience, keyboard rarely fail. I even put some hold laptop keyboard in dishwasher to clean out some pepsi and stuff… and it worked ! Now dont try that last one with yours, the case would not survive. I hope you find a way.