Certain letters on Magic Keyboard not working
I am unable to type the letters c m n x or z in lower or upper case on my Magic Keyboard
connected to my iPad Pro. This started happening a week ago.
Sounds like the keyboard may be suffering hardware failure. Have you tried to use it on another iPad. I would suggest either finding someone that has a device similar and hook up to it and see if it suffers the same issues, or take it to a Genius Bar at a Apple Store and have them connect it to a device there and test it. They’ll be able to tell you the next steps as well.