Comment 26 for bug 1814481

Keychron K1v3 (firmware V3.7) on Ubuntu 19.10 (upgrad path from 18.04), can confirm that https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1814481/comments/19 fixes the issue when connected via Bluetooth.

Some additional information: For me when connected via Bluetooth only the function keys would work. The following command as described by Eferox, allowed me to use the keyboard normally:

    echo 0 | sudo tee /sys/module/hid_apple/parameters/fnmode

Note that this means that the `fn` key is now disabled by default, so pressing one of the `F<num>` keys registers as `F1`, `F2`, etc. In order to get the media key functions you have to press `fn` + `F<num>`. Also note that if you also use an Apple keyboard this probably modifies its default behaviour.

Explanation of parameters for `/sys/module/hid_apple/parameters/fnmode`
https://superuser.com/questions/79822/how-to-swap-the-fn-use-of-function-keys-on-an-apple-keyboard-in-linux