Disable Keychron’s Fn Keys

# To disable it
echo 0 | sudo tee /sys/module/hid_apple/parameters/fnmode

# To enable it
echo 1 | sudo tee /sys/module/hid_apple/parameters/fnmode

Source: https://www.reddit.com/r/MechanicalKeyboards/comments/d5io49/keychron_k2_f_keys_dont_work_w_linux_help/f0m2u14