I have the exact same Logitech C922 webcam as you have.
I see similar messages in my logs, although they are not all in the systemd journal, as my system is a Debian 10.
These particular messages are created by the X11 display server.
[ 121.255] (II) config/udev: Adding input device C922 Pro Stream Webcam (/dev/input/event31)
[ 121.255] (**) C922 Pro ...
Your Jabra earphone apparently includes some buttons that are presented to the OS as a "keyboard-like" input device, and apparently your desktop environment will reset the X11 keyboard layout whenever new keyboard devices are plugged in, according to the settings it knows about.
Your setxkbmap settings will not be known to the desktop environment, ...