Hello,
Your keyboard should be a wireless Bluetooth and USB wired keyboard 2-in-1 keyboard.
Flashing "X" , this means your keyboard is in wireless Bluetooth mode, it is waiting for another Bluetooth peripherals to pair with it. Now if you don't want to use it as a wireless Bluetooth keyboard, you just need to click Fn+X, then the keyboard will go back to be in USB wired mode, then it will be used as a USB wired keyboard.
Edited: 1 year ago
Working