9 key does not work

Hello! My 9 key does not work in Linux or Windows.
Could you please give me some troubleshooting steps I should follow?
I unscrewed the top and bottom plates and did not see anything visibly wrong with it.

Please email help@keyboard.io.

You can also check the built-in test mode to see what it sees about the 9 key. See this thread for more info about the test mode:

Thank you very much, algernon!
I did the test, and the 9 key remained red.
I am emailing help@keyboard.io right now.

Edit: Since the keyboard comes with an any key, I configured it to output a 9 key.
Also, I held the keyboard upside-down and pressed the key 20 times. It totally worked!