If your keyboard is not working in the cable mode, make sure you have followed these steps properly:
1/ Make sure you switch the toggle from Bluetooth to the Cable mode.
2/ Try to use the keyboard in cable mode with another laptop/ device.
3/ Make sure your laptop/ device's software is installed and up-to-date.
4/ Try connecting your keyboard directly to your computer, bypassing any USB hubs.
If it still does not work, send us a video at support@keychron.com
Thanks.