I fixed it on my machine with german keyboard the following way, after some research here and on the archwiki…
- Create the file /etc/udev/hwdb.d/90-purism-german-keyboard-fix.hwdb with content:
evdev:atkbd:dmi:bvn*:bvr*:bd*:svnPurism*:pn*Librem13v2*:pvr*
KEYBOARD_KEY_56=86
- systemd-hwdb update
- udevadm trigger